Semiconductor device and electronic apparatus including a semiconductor device having bonded sensor and logic substrates

ABSTRACT

A solid-state imaging device has a sensor substrate having a pixel region on which photoelectric converters are arrayed; a driving circuit provided on a front face side that is opposite from a light receiving face as to the photoelectric converters on the sensor substrate; an insulation layer, provided on the light receiving face, and having a stepped construction wherein the film thickness of the pixel region is thinner than the film thickness in a periphery region provided on the outside of the pixel region; a wiring provided to the periphery region on the light receiving face side; and on-chip lenses provided to positions corresponding to the photoelectric converters on the insulation layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/087,918, filed Mar. 31, 2016 which is a continuation of U.S. patentapplication Ser. No. 14/841,958, filed Sep. 1, 2015, which is acontinuation of U.S. patent application Ser. No. 13/547,698, filed Jul.12, 2012, now U.S. Pat. No. 9,153,490, which claims priority to JapanesePatent Application No. JP 2011-157977, Japanese Patent Application No.JP 2011-162228, and Japanese Patent Application No. JP 2011-196785,filed in the Japan Patent Office on Jul. 19, 2011, Jul. 25, 2011, andSep. 9, 2011, respectively, the entire disclosures of which are herebyincorporated herein by reference.

BACKGROUND

The present disclosure relates to a solid-state imaging device,manufacturing method of a solid-state imaging device, manufacturingmethod of a semiconductor device, a semiconductor device, and anelectronic device.

An electronic device such as a digital video camera, digital stillcamera, and the like include a semiconductor device such as asolid-state imaging device. For example, a solid-state imaging deviceincludes a CMOS (Complementary Metal Oxide Semiconductor)-type imagesensor and CCD (Charge Coupled Device)-type image sensor.

A solid-state imaging device has multiple pixels arrayed on a face of asemiconductor substrate. A photoelectric converter is provided to eachpixel. The photoelectric converter is a photodiode, for example, andgenerates signal load by receiving the incident light via an externaloptical system with a light-receiving face and performing photoelectricconversion.

With the solid-state imaging device, generally, the photoelectricconverter receives incident light at a front face side on which acircuit or wiring has been provided to the semiconductor substrate. Insuch a case, the circuit and wiring blocks the incident light, andaccordingly there are cases wherein improving sensitivity is difficult.Therefore, a “rear projection type” has been proposed, wherein thephotoelectric converter receives the incident light at a rear side whichis on the opposite side from the front face on which the circuit andwiring has been provided to the semiconductor substrate (e.g., referenceJapanese Unexamined Patent Application Publication No. 2005-150463 andJapanese Unexamined Patent Application Publication No. 2008-182142).

Also, with a semiconductor device such as the solid-state imaging devicedescribed above, “three-dimensional packaging” has been proposed,wherein multiple substrates, on which devices with differing functionshave been provided, are layered and electrically connected to oneanother. With “three-dimensional packaging”, an optimal circuitcorresponding to each function is formed on each substrate, wherebyimproving the device function can be readily realized. For example, asensor substrate on which a sensor device is provided and a logicsubstrate on which a logic circuit for processing signals output fromthe sensor device thereof are layered to configure a solid-state imagingdevice. Now, a pad opening is provided by perforating the semiconductorsubstrate so that the front face of the pad wiring is exposed, and byfilling conductive material in the pad opening thereof, the devices areelectrically connected with one another. That is to say, the sensorsubstrate and logic substrate are electrically connected to each othervia TSV (Through Silicon Via) (e.g., Japanese Unexamined PatentApplication Publication No. 2010-245506).

Further, U.S. Pat. No. 4,349,232 discloses a solid-state imaging devicewherein a signal processing chip is layered onto a sensor chip, andJapanese Unexamined Patent Application Publication No. 2008-182142discloses a technique to electrically connect a sensor chip in asemi-manufactured state and a signal processing chip in asemi-manufactured state to have a completed product.

SUMMARY

However, with the semiconductor device such as the above-describedsolid-state imaging device, in the case that improving the devicereliability or product yield sufficiently is difficult, or with asolid-state imaging device constructed by layering a signal processingchip onto a sensor chip, a configuration is used wherein a transistorbelonging to a logic circuit is disposed in the vertical direction as toa pixel on the sensor chip. With such a configuration, adverse effectsof light emitted by a hot carrier (a carrier having obtained energy bythe expansion of an electric field within a transistor (electron orhole)), in a transistor belonging to the logic circuit is a concern.That is to say, upon light emitted by the hot carrier being detected bya pixel on the sensor chip, the light appears in the image as noise, andcan cause the image quality to deteriorate.

Accordingly, the present technology provides a manufacturing method of asemiconductor device, a semiconductor device, and an electronic devicewherein improvements can be made to the device reliability,manufacturing yield, and so forth.

According to the present technology described above, with a solid-stateimaging device of a rear-projection type wherein wiring is provided inthe periphery region of the outer side of the pixel region, byselectively chasing the insulation layer portion of the pixel region tobecome thinner, the distance between an on-chip lens and the lightreceiving face can be reduced. As a result, light receiving propertiesof the photoelectric converter can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram illustrating an example of asolid-state imaging device to which the present technology is to beapplied;

FIG. 2 is a principal portion cross-sectional diagram illustrating aconfiguration of the solid-state imaging device according to a firstembodiment;

FIGS. 3A and 3B are cross-sectional process diagrams (part 1)illustrating manufacturing procedures of the solid-state imaging deviceaccording to the first embodiment;

FIGS. 4A and 4B are cross-sectional process diagrams (part 2)illustrating manufacturing procedures of the solid-state imaging deviceaccording to the first embodiment;

FIGS. 5A through 5C are cross-sectional process diagrams (part 3)illustrating manufacturing procedures of the solid-state imaging deviceaccording to the first embodiment;

FIGS. 6A through 6C are cross-sectional process diagrams (part 4)illustrating manufacturing procedures of the solid-state imaging deviceaccording to the first embodiment;

FIG. 7 is a principal portion cross-sectional diagram illustrating aconfiguration of the solid-state imaging device according to a secondembodiment;

FIGS. 8A through 8C are cross-sectional process diagrams (part 1)illustrating manufacturing procedures of the solid-state imaging deviceaccording to the second embodiment;

FIGS. 9A and 9B are cross-sectional process diagrams (part 2)illustrating manufacturing procedures of the solid-state imaging deviceaccording to the second embodiment;

FIGS. 10A and 10B are cross-sectional process diagrams (part 3)illustrating manufacturing procedures of the solid-state imaging deviceaccording to the second embodiment;

FIG. 11 is a principal portion cross-sectional diagram illustrating aconfiguration of the solid-state imaging device according to a thirdembodiment;

FIGS. 12A through 12C are cross-sectional process diagrams (part 1)illustrating manufacturing procedures of the solid-state imaging deviceaccording to the third embodiment;

FIGS. 13A and 13B are cross-sectional process diagrams (part 2)illustrating manufacturing procedures of the solid-state imaging deviceaccording to the third embodiment;

FIG. 14 is a principal portion cross-sectional diagram illustrating aconfiguration of the solid-state imaging device according to a fourthembodiment;

FIGS. 15A through 15C are cross-sectional process diagrams (part 1)illustrating manufacturing procedures of the solid-state imaging deviceaccording to the fourth embodiment;

FIGS. 16A through 16C are cross-sectional process diagrams (part 2)illustrating manufacturing procedures of the solid-state imaging deviceaccording to the fourth embodiment;

FIG. 17 is a principal portion cross-sectional diagram illustrating aconfiguration of the solid-state imaging device according to a fifthembodiment;

FIG. 18 is a diagram illustrating a configuration of the principalportions of a solid-state imaging device according to a sixthembodiment;

FIG. 19 is a diagram illustrating a configuration of the principalportions of the solid-state imaging device according to the sixthembodiment;

FIG. 20 is a diagram illustrating a configuration of the principalportions of the solid-state imaging device according to the sixthembodiment;

FIG. 21 is a diagram illustrating a configuration of the principalportions of the solid-state imaging device according to the sixthembodiment;

FIG. 22 is a diagram illustrating the principal portions regarding amanufacturing method of the solid-state imaging device according to thesixth embodiment;

FIG. 23 is a diagram illustrating the principal portions regarding amanufacturing method of the solid-state imaging device according to thesixth embodiment;

FIG. 24 is a diagram illustrating the principal portions regarding amanufacturing method of the solid-state imaging device according to thesixth embodiment;

FIG. 25 is a diagram illustrating the principal portions regarding amanufacturing method of the solid-state imaging device according to thesixth embodiment;

FIG. 26 is a diagram illustrating the principal portions regarding amanufacturing method of the solid-state imaging device according to thesixth embodiment;

FIG. 27 is a diagram illustrating the principal portions regarding amanufacturing method of the solid-state imaging device according to thesixth embodiment;

FIG. 28 is a diagram illustrating the principal portions regarding amanufacturing method of the solid-state imaging device according to thesixth embodiment;

FIG. 29 is a diagram illustrating the principal portions regarding amanufacturing method of the solid-state imaging device according to thesixth embodiment;

FIG. 30 is a diagram illustrating the principal portions regarding amanufacturing method of the solid-state imaging device according to thesixth embodiment;

FIG. 31 is a diagram illustrating the principal portions regarding amanufacturing method of the solid-state imaging device according to thesixth embodiment;

FIG. 32 is a diagram illustrating a comparative example situationaccording to the sixth embodiment;

FIGS. 33A through 33C are diagrams illustrating a comparative examplesituation according to the sixth embodiment;

FIG. 34 is a perspective diagram illustrating connective wiring ofconnected conductive layers according to the sixth embodiment;

FIG. 35 is a diagram illustrating a portion wherein a concave portion ofconnective wiring has been provided, according to the sixth embodiment;

FIG. 36 is a diagram illustrating a configuration of the principalportions of a solid-state imaging device according to an eighthembodiment;

FIG. 37 is a cross-sectional diagram illustrating a configurationexample of a layered-type imaging device;

FIG. 38 is a cross-sectional diagram illustrating a layered-type imagingdevice in a configuration example according to the related art;

FIG. 39 is a diagram illustrating an example of wiring design rules;

FIG. 40 is a diagram illustrating the relation between width of ablocking film and minimum spacing according to the design rules;

FIGS. 41A through 41D are diagrams illustrating a blocking film layoutformed so as to have the maximum duty ratio;

FIG. 42 is a diagram illustrating blocking capability by each layout;

FIGS. 43A and 43B are diagrams illustrating an example of a blockingfilm laid out in two patterns;

FIGS. 44A and 44B are diagrams illustrating a configuration example of ablocking film in a two-layer configuration;

FIG. 45 is a diagram illustrating blocking capability when the blockingfilm is laid out in two patterns;

FIG. 46 is a diagram illustrating the relation between shifting amountof the blocking firm disposal cycle and the blocking capability;

FIG. 47 is a diagram describing a blocking film layout that employs aline shape;

FIG. 48 is a diagram illustrating the blocking capability in a blockingfilm layout that employs a line shape;

FIG. 49 is a diagram describing a layout wherein only the portions thatare spaces in the first layer of blocking film have the second layer ofblocking film disposed;

FIG. 50 is a diagram illustrating the relation between overlap width andblocking capability;

FIG. 51 is a diagram illustrating a planar configuration of a wiringlayer; and

FIG. 52 is a configuration diagram of an electronic device using asolid-state imaging device obtained by applying the present technology.

DETAILED DESCRIPTION OF EMBODIMENTS

Schematic Configuration Example of Solid-State Imaging Device Accordingto an Embodiment

FIG. 1 shows a schematic configuration of a three-dimensionalconstruction solid-state imaging device, serving as an example of arear-projection type of solid-state imaging device to which the presenttechnology is applied. A solid-state imaging device 1 shown in this FIG.1 has a sensor substrate 2 formed with photoelectric converters arrayed,and a circuit substrate 9 that is bonded onto the sensor substrate 2 inthe state of being layered thereto.

The sensor substrate 2 has a pixel region 4 wherein one face is a lightreceiving face A and multiple pixels 3 including photoelectricconverters are arrayed two-dimensionally as to the light receiving faceA. On the pixel region 4, multiple pixel driving lines 5 are arrayed inthe row direction and multiple vertical signal lines 6 are arrayed inthe column direction, and one pixel 3 is disposed so as to be connectedto one pixel driving line 5 and one vertical signal line 6. Aphotoelectric converter, a load accumulating unit, and a pixel circuitmade up of multiple transistors (so-called MOS transistors) andcapacitors and the like are provided to each pixel 3. Note that aportion of the pixel circuit is provided on the front face side on theopposite side from the light receiving face A. Also, multiple pixels mayshare a portion of the pixel circuit.

Also the sensor substrate 2 has a periphery region 7 on the outer sideof the pixel region 4. A wiring 8 including an electrode pad is providedto the periphery region 7. The wiring 8 is connected to the pixeldriving lines 5, vertical signal lines 6, and pixel circuit, and furtherto the driving circuit provided to the circuit substrate 9, as suitable.

The circuit substrate 9 has, on one face side facing the sensorsubstrate 2 side, driving circuits such as a vertical driving circuit 10to drive the pixels 3 provided to the sensor substrate 2, a columnsignal processing circuit 11, vertical driving circuit 12, and systemcontrol circuit 13 and so forth. The driving circuits herein areconnected to the wiring 8 on the sensor substrate 2 side. Note that thepixel circuit provided to the front face side of the sensor substrate 2is a portion of the driving circuit.

First Embodiment

Configuration of Solid-State Imaging Device

Example Providing Insulation Layer and Embedded Wiring in SteppedConstruction

FIG. 2 is a principal portion cross-sectional diagram showing aconfiguration of a solid-state imaging device 1-1 according to a firstembodiment, and is a cross sectional diagram near the border between thepixel region 4 and periphery region 7 in FIG. 1. A configuration of thesolid-state imaging device 1-1 according to the first embodiment will bedescribed below, based on the principal portion cross-sectional diagramherein.

The solid-state imaging device 1-1 according to the first embodimentshown in FIG. 2 is a solid-state imaging device in a three-dimensionalconstruction bonded together in the state wherein the sensor substrate 2and circuit substrate 9 are layered, as described above. On the frontface side of the sensor substrate 2, i.e. the face facing the circuitsubstrate 9 side, is provided a wiring layer 2 a and a protective film 2b that covers the wiring layer 2 a. On the other hand, on the surfaceside of the circuit substrate 9, i.e. the face facing the sensorsubstrate 2 side, is provided a wiring layer 9 a and a protective film 9b that covers the wiring layer 9 a. Also, on the back face side of thecircuit substrate 9, a protective film 9 c is provided. The sensorsubstrate 2 and circuit substrate 9 herein are bonded together betweenthe protective film 2 b and protective film 9 b.

Also, on the face that is the opposite side from the circuit substrate 9on the sensor substrate 2, i.e., the light receiving face A, aninsulation layer 14 having a stepped construction, a wiring 8, and ablocking film 16 are provided, and further on the blocking film 16, atransparent protective film 17, color filter 18, and on-chip lens 19 arelayered in this order. According to the present first embodiment, aparticular feature is that the insulation layer 14 has a steppedconstruction, and the on-chip lens 19 is disposed on the lower portionof the stepped construction herein.

Next, configurations of the layers on the sensor substrate 2 side andthe layers on the circuit substrate 9 side, and a configuration of theinsulation layer 14 having a stepped construction, the wiring 8,blocking film 16, transparent protective film 17, color filter 18, andon-chip lens 19 will be described in sequence herein.

Sensor Substrate 2

The sensor substrate 2 is a semiconductor substrate made fromsingle-crystal silicon that has been made into a thin film, for example.Multiple photoelectric converters 20 are arrayed along the lightreceiving face A in the pixel region 4 on the sensor substrate 2. Thephotoelectric converters 20 are configured in a layered constructionbetween a n-type dispersion layer and p-type dispersion layer, forexample. Note that a photoelectric converter 20 is provided for eachpixel, and the diagram shows a cross-section of one pixel.

Also, on the front face size that is opposite from the light receivingface A on the sensor substrate 2, a source/drain 21 of a floatingdiffusion FD made from a n+ type impurity layer and a transistor Tr, andfurther another impurity layer omitted from the diagram herein anddevice separation 22 and so forth are provided.

Further, on the sensor substrate 2, a through via 23 that passes throughthe sensor substrate 2 is provided to the periphery region 7 on theouter side of the pixel region 4. The through via 23 is made withconductive material that fills in a connecting hole formed through thesensor substrate 2 via the separation insulating film 24.

Wiring Layer 2 a (Sensor Substrate 2 Side)

The wiring layer 2 a provided on the front face of the sensor substrate2 has a gate electrode 25 of a transfer gate TG and transistor Tr via agate insulating film omitted in the drawings herein, and further otherelectrodes omitted in the drawings herein, on the interface side withthe sensor substrate 2. Also, the transfer gate TG and gate electrode 25are covered with an inter-layer insulating film 26, and embedded wirings27 using copper (Cu), for example, are provided as multi-layer wiring,in a groove pattern provided in the inter-layer insulating film 26. Theembedded wirings 27 are mutually connected with a via, and areconfigured so that a portion thereof is connected to the source/drain21, transfer gate TG, and gate electrode 25. Also, a through via 23provided to the sensor substrate 2 is also connected to the embeddedwiring 27, and a pixel circuit is configured with the transistor Tr andembedded wiring 27 and so forth.

An insulating protective film 2 b is provided on top of the inter-layerinsulating film 26 wherein the above-described embedded wiring 27 isformed, and on the protective film 2 b surface, the sensor substrate 2is bonded to the circuit substrate 9.

Circuit Substrate 9

The circuit substrate 9 is a semiconductor substrate made fromsingle-crystal silicon that has been made into a thin film, for example.On the front face layer facing the sensor substrate 2 side of thecircuit substrate 9, a source/drain 31 of a transistor Tr, and furtheran impurity layer omitted from the diagram herein and device separation32 and so forth are provided.

Further, a through via 33 is provided through the circuit substrate 9.The through via is made with conductive material that fills in theconnecting hole formed through the circuit substrate 9, via a separatinginsulating film 34.

Wiring Layer 9 a (Circuit Substrate 9 Side)

The wiring layer 9 a provided on the front face of the circuit substrate9 has a gate electrode 35 provided via a gate insulating film omitted inthe diagram herein and further another electrode omitted in the diagramherein, on the side interfacing with the circuit substrate 9. The gateelectrode 35 and other electrode are covered with an inter-layerinsulating film 36, and embedded wirings 37 using copper (Cu), forexample, are provided as multi-layer wiring, in a groove patternprovided in the inter-layer insulating film 36. The embedded wirings 37are mutually connected with a via, and are configured so that a portionthereof is connected to the source/drain 31 and gate electrode 35. Also,a through via 33 provided to the circuit substrate 9 is also connectedto the embedded wiring 37, and a driving circuit is configured with thetransistor Tr and embedded wiring 37 and so forth.

An insulating protective film 9 b is provided on top of the inter-layerinsulating film 36 wherein the above-described embedded wiring 37 isformed, and on the protective film 9 b front face, the circuit substrate9 is bonded to the sensor substrate 2. Also, on the back face side ofthe circuit substrate 9 which is opposite from the front face side onwhich the wiring layer 9 a is provided, a protective film 9 c whichcovers the circuit substrate 9 is provided, and a pad opening 33 a whichexposes the through via 33 is provided to the protective film 9 c.

Insulation Layer 14

The insulation layer 14 is provided on top of the light receiving face Aof the sensor substrate 2. A feature of the insulation layer 14 is inhaving a stepped construction wherein the film thickness of the pixelregion 4 is thinner than the film thickness of the periphery region 7.This insulation layer 14 is configured as a layering film usingdifferent insulating materials, for example, and as an example, is madeof five layers, in sequence from the light receiving face A side, of areflection preventing film 14-1, interface level suppressing film 14-2,etching stopping film 14-3, groove forming film 14-4, and capping film14-5.

The reflection preventing film 14-1 is configured using an insulatingmaterial having a higher refractive index than silicon oxide, such ashafnium oxide (HfO₂), tantalum oxide (Ta₂O₅), silicon nitride, and thelike. The interface level suppressing film 14-2 is configured usingsilicon oxide (SiO₂), for example. The etching stopping film 14-3 uses amaterial whereby the etching selection ratio is kept low as compared tothe material used for upper layer of the groove-forming film 14-4, andfor example is configured using silicon nitride (SiN). Thegroove-forming film 14-4 is configured using silicon oxide (SiO₂), forexample. The capping film 14-5 is configured using silicon nitride(SiN), for example.

This five-layer construction of an insulation layer 14, in the pixelregion 4, is thinned by removing the upper layer portion of the cappingfilm 14-5, groove-forming film 14-4, and etching stopping film 14-3 tohave a two-layer construction of the reflection preventing film 14-1 andinterface level suppressing film 14-2. On the other hand, in the thickfilm portion at the periphery region 7, a wiring groove that provides awiring 8 within, to be described next, is formed on the groove-formingfilm 14-4 which is the second layer from the top.

Wiring 8

The wiring 8 is provided as an embedded wiring that is embedded in theinsulation layer 14, as the periphery region 7 on the light receivingface A side. The wiring 8 is embedded in a wiring groove that is formedin the groove forming film 14-4 that is included in the insulation layer14, and is connected to the through via 23 which is provided through thelower layers of the etching stopping film 14-3, interface levelsuppressing film 14-2, and reflection preventing film 14-1.

This wiring 8 and through via 23 are configured in an integrated manner,via a wiring groove formed on the groove forming film 14-4 and theseparating insulating film 24 that continuously covers the inner wall ofthe connecting hold in the layer therebelow, so as to fill in copper(Cu) in the wiring groove and connecting hole. The separating insultingfilm is configured using a material a dispersion preventing function ofthe copper (Cu) such as a silicon nitride, for example. Note that theupper portion of the wiring 8 is in a state of being covered with acapping film 14-5 making up the uppermost layer of the insulation layer14.

Blocking Film 16

The blocking film 16 is provided to the lower portion of the steppedportion of the insulation layer 14 of the pixel region 4 on the lightreceiving face A side, i.e., above of the interface level suppressionfilm 14-2 that is included in the lower layer portion of the layeredconstruction of the insulation layer 14. This blocking film 16 hasmultiple light receiving openings 16 a that correspond to thephotoelectric converters 20.

This light blocking film 16 is configured using a conductive materialwith excellent light blocking, such as aluminum (Al) or tungsten (W),and is provided in a state of being grounded as to the sensor substrate2 at the openings provided to the insulation layer 14.

Transparent Protection Film 17

The transparent protection film 17 is provided in a state of coveringthe insulation layer 14 and the blocking film 16. Acrylic resin or thelike, for example, is used for the transparent protection film 17.

Color Filter 18

The color filter 18 is provided so as to correspond to the photoelectricconverters 20, and includes colors corresponding to the photoelectricconverters 20. The array of the color filter 18 for each color is notrestricted.

On-Chip Lens 19

The on-chip lens 19 is provided so as to correspond to the photoelectricconverters 20, and is configured so that the incident light is collectedin the photoelectric converters 20.

Manufacturing Method of Solid-State Imaging Device

Next, a manufacturing method of the solid-state imaging device 1-1 inthe above-described configuration will be described based on thecross-sectional process diagrams in FIGS. 3 through 6.

FIG. 3A

First, as shown in FIG. 3A, multiple photoelectric converters 20 arearrayed in the pixel region 4 of the sensor substrate 2, and also animpurity layer such as a floating diffusion FD and device separation 22are formed thereupon. Next, a transfer gate TG and gate electrode 25 areformed on the front face of the sensor substrate 2, and further, anembedded wiring 27 and an inter-layer insulating film 26 are formed toprovide a wiring layer 2 a, and the upper portion of the wiring layer 2a is covered with a protective film 2 b. On the other hand, an impuritylayer such as a source/drain 31 and device separation 32 are formedthereupon. Next, a gate electrode 35 is formed on the front face of thecircuit substrate 9, and further, an embedded wiring 37 and aninter-layer insulating film 36 are formed to provide a wiring layer 9 a,a via 33 is formed from the wiring layer 9 a to the circuit substrate 9,and the upper portion of the wiring layer 9 a is covered with aprotective film 9 b.

After the above, the sensor substrate 2 and circuit substrate 9 arebonded together between the protective film 2 b and protective layer 9b. After the bonding together has ended, the light receiving face A sideof the sensor substrate 2 is caused to be a thin film as suitable. Theprocess up to this point does not have particular restrictions to theprocedures, and bonding can be performed applying normal techniques.

FIG. 3B

As shown in FIG. 3B, a reflection preventing film 14-1, interface levelsuppressing film 14-2, etching stopping film 14-3, and groove formingfilm 14-4 are formed in layers, in this order, on the light receivingface A of the sensor substrate 2. The reflection preventing film 14-1 ismade of hafnium oxide (HfO₂), for example, and is formed in a filmthickness of 10 nm to 300 nm (e.g. 60 nm) by Atomic Layer Deposition.The interface level suppressing film 14-2 is made of silicon oxide(SiO₂), for example, and is formed in a film thickness of 200 nm with aP-CVD (plasma-chemical vapor deposition) method. The etching stoppinglayer 14-3 is made of silicon nitride (SiN), for example, and is formedin a film thickness of 360 nm with a P-CVD method. The groove formingfilm 14-4 is made of silicon oxide (SiO₂), for example, and is formed ina film thickness of 200 nm with a P-CVD method.

The above four layers are formed as a film that makes up a portion ofthe insulation layer (14) having the above-described steppedconstruction.

FIG. 4A

Subsequently, as shown in FIG. 4A, a wiring groove 8 a is formed on theuppermost layer of the groove forming film 14-4 in the periphery region7 of the sensor substrate 2. In this event, etching is performed on thegroove forming film 14-4 that is made of silicon oxide (SiO₂), using theresist pattern, which is omitted in the diagram here, as a mask. In theetching herein, the etching is stopped with the etching stopping film14-3 which is made of a lower layer of silicon nitride (SiN). Uponending the etching, the resist pattern is removed.

FIG. 4B

Next, as shown in FIG. 4B, connecting holes 23 a are formed in depths asappropriate, in the floor portion of the wiring groove 8 a. Theconnecting holes 23 a only have to be formed at the depths reaching thetop of the embedded wiring 27 of the wiring layer 2 a or the embeddedwiring 37 of the wiring layer 9 a, and do not have to expose theembedded wiring 27 and embedded wiring 37 to the floor portion. In thisevent, for each depth of the connecting holes 23 a, multiple resistpatterns, which are omitted in the diagram herein, are formed, andetching is performed multiple times as to the sensor substrate 2 andinter-layer insulating film 26, using the resist patterns herein asmasks. Upon ending each etching, the resist patterns are removed.

FIG. 5A

Next, as shown in FIG. 5A, a separating insulating film 24 is formed onthe groove forming film 14-4 in the state of covering the inner wall ofthe wiring groove 8 a or the connecting hole 23 a. Now, let us say thata separating insulating film 24 in a two-layer construction will beformed, for example, wherein first, a silicon nitride film 24-1 of afilm thickness of 70 nm will be formed with the p-CVD method, and next,a silicon oxide film 24-2 of a film thickness of 900 nm will be formedwith the p-CVD method. Note that the separating insulating film 24 isnot restricted as to the layered construction, and may have asingle-layer construction of a silicon oxide film or silicon nitridefilm, for example.

FIG. 5B

Subsequently, as shown in FIG. 5B, by etching to remove the separatinginsulating film 24 under etching conditions having high anisotrophy, thefloor portions of the groove forming film 14-4 and wiring grooves 8 aand the separating insulating film 24 of the floor portions of theconnecting holes 23 a are removed. Next, the inter-layer insulating film26 of the floor portions of the connecting holes 23 a, the protectivefilm 2 b, and the protective film 9 b are removed by etching, andetching of the connecting holes 23 a is further advanced. Thus, theembedded wiring 27 or embedded wiring 37 is exposed to the floor portionof the connecting holes 23 a.

Note that with such etching, in the case that the inter-layer insultingfilm 26 is made of a silicon oxide film, the front face layer of thegroove forming film 14-4 that is made of silicon oxide which is a lowerlayer of the separating insulating film 24 is also reduced by etching.Also, in the case that the protective film 2 b and protective film 9 bare made of a silicon nitride film, the etching stopping film 14-3 madeof silicon nitride on the floor portion of the wiring groove 8 a is alsoreduced by etching. Accordingly, with consideration for the amount ofreduction herein, the film thicknesses at the time of forming the filmsof the etching stopping film 14-3 made of silicon nitride and the grooveforming film 14-4 made of silicon oxide are set.

FIG. 5C

Next, as shown in FIG. 5C, by filling in the wiring groove 8 a andconnecting holes 23 a with a conductive material so as to be integrated,the wiring 8 is formed as embedded wiring within the wiring groove 8 a,and a through via 23 is formed within the connecting hole 23 a thatpasses through the sensor substrate 2. Now, first, a conductive materialfilm (e.g., copper (Cu) film) is formed on the groove forming filming14-4 while in the state of filling in the wiring groove 8 a andconnecting holes 23 a, and next polishes to remove the conductivematerial film on the groove forming film 14-4 with a chemical mechanicalpolishing (CMP) method. Thus, the conductive material film remains onlywithin the wiring groove 8 a and connecting holes 23 a, and a throughvia 23 is formed in the periphery region 7 on the light receiving face Aside of the sensor substrate 2 which connects the wiring 8 hereto.

FIG. 6A

Next, as shown in FIG. 6A, a capping film 14-5 having a dispersionpreventing effect as to the copper (Cu) which the wiring 8 is made of isformed, in the state of covering the wiring 8 and groove forming film14-4. Now, as a capping film 14-5, for example a silicon nitride film isformed at a film thickness of 70 nm. Thus, an insulation layer 14 in afive-layer construction is formed on the light receiving face A of thesensor substrate 2, in a layered manner in the order of a reflectionpreventing film 14-1, interface level suppressing film 14-2, etchingstopping film 14-3, groove forming film 14-4, and capping film 14-5.Note that on top of the uppermost capping film 14-5 made of siliconnitride, another silicon oxide film may be formed as appropriate.

FIG. 6B

Subsequently, as shown in FIG. 6B, the portion corresponding to thepixel region 4 in the insulation layer 14 is selectively caused to be athinner film as compared to the periphery region 7, and thus forms astepped construction in the insulation layer 14. In this event, thecapping film 14-5 made of silicon nitride (SiN) is etched, using theresist pattern which is omitted in the diagram as a mask, and thereafterconditions are changed to etch the groove forming film 14-4 made ofsilicon oxide (SiO₂). In this event, the etching is stopped with theetching stopping film 14-3 of a lower layer made of silicon nitride(SiN). Subsequently, the conditions are further changes to etch theetching stopping film 14-3.

Thus, the insulation layer 14 on the light receiving face A has astepped construction wherein the film thickness of the pixel region 4 isthinner than the film thickness of the periphery region 7, and has acavity construction wherein the film is thin on the pixel region 4. Insuch a state, only the reflection preventing film 14-1 and interfacelevel suppressing film 14-2 remain in the pixel region 4. On the otherhand, insulation layer 14 in a five-layer construction remains withoutchange in the periphery region 7. Also, the step in the steppedconstruction of the insulation layer 14 is approximately 500 nm.

Note that the thin film portion in the insulation layer 14 may be set tohave a wide range, in a range in which there is no influence on thewiring 8, thereby preventing influence on incident light to thephotoelectric converters 20 due to the stepped form of the insulationlayer 14 worsening the unevenness in the coating of the transparent flatfilm to be formed hereafter.

FIG. 6C

Next, as shown in FIG. 6C, on the lower portion of the stepped of theinsulation layer 14, openings 14 a that expose the sensor substrate 2are formed. In this event, the interface level suppression film 14-2 andreflection preventing film 14-1 are etched, using a resist pattern whichhas been omitted in the diagram herein as a mask. Note that the openings14 a are formed in positions avoiding the upper side of thephotoelectric converters 20.

Next, the blocking film 16 that has been grounded to the sensorsubstrate 2 via the openings 14 a is caused to form a pattern on thelower portion of the step of the insulation layer 14. The blocking film16 herein has a light receiving opening 16 a that corresponds to thephotoelectric converter 20. Now, first, a conductive material filmhaving blocking capability such as aluminum (Al) or tungsten (W) isformed on top of the insulation layer 14 with a sputtering film formingmethod. Subsequently, by etching a pattern on the conductive materialfilm using the resist pattern omitted from the diagram herein as a mask,the lower portion of the step is widely coated, and the blocking film16, which has a light receiving opening 16 a corresponding to eachphotoelectric converter, has been grounded to the sensor substrate 2.

This light blocking film 16 may be in a form of being removed on theupper portion of the step of the insulation layer 14, and widely coatingthe lower portion of the step. Thus, the stepped form in the insulationlayer 14 is reduced over a wide range.

FIG. 2

Subsequent to the above, as shown in FIG. 2, a transparent protectivefilm 17 made of a material having light permeability is formed in astate of covering the blocking film 16. The transparent protective film17 is formed with a coating method such as a spin-coating method. Next,color filters 18 in colors corresponding to the photoelectric converters20 are formed on the transparent protective film 17, and further,on-chip lenses 19 that correspond to the photoelectric converters 20 areformed thereupon. Also, the circuit substrate 9 is caused to be thinner,by polishing the exposed face of the circuit substrate 9, and the via 33is exposed so as to become a through via 33. Subsequently, theprotective film 9 c is formed on top of the circuit substrate 9 in astate of covering the through via 33, and a pad opening 33 a thatexposes the through via 33 is formed, thereby completing the solid-stateimaging device 1-1.

Advantages of First Embodiment

The solid-state imaging device 1-1 in the configuration described aboveis a rear-projection type of solid-state imaging device having provideda wiring 8 in the periphery region 7 on the outer side of the pixelregion 4. In such a configuration, an insulation layer 14 in a steppedconstruction wherein the film thickness of the pixel region 4 is thinnerthan that of the periphery region 7 is provided on top of the lightreceiving face A, and an on-chip lens 19 is provided on top thereof.Thus, in the periphery region 7, the film thickness of the insulationlayer 14 can be secured without influencing the configuration of thewiring 8, and on the other hand, in the pixel region 4, the insulationlayer 14 can be made thinner and the distance between the on-chip lens19 thereupon and the light receiving face A can be reduced.

Now, as in constructions in related art, if the configuration has theblocking film covered with an insulating film, and a wiring is providedon top of the insulating film, an insulating film is provided in a stateof covering the wiring, and an on-chip lens is disposed on top thereof.Therefore, the on-chip lens has been disposed on top of the lightreceiving face, via at least two layers of insulating films, andaccordingly the distance from the light receiving face to the on-chiplens has been great, causing deterioration in the light receptionproperties of the photoelectric converters. Additionally, the patternform of the blocking film is transferred to the front face of theinsulating film formed on top of the blocking film, and accordingly inthe case of forming a wiring groove to form embedded wiring as to suchan insulating film, accurate patterning becomes difficult. Thus, byforming a flat insulation layer on top of the blocking film, accuracy ofthe patterning for forming wiring grooves can be secured. However, thedistance from the light receiving face to the on-chip lens becomesgreater due to the flat insulating film, and accordingly light receptionproperties by the photoelectric converters further deteriorates.

Conversely, the manufacturing method according to the above-describedfirst embodiment is a procedure whereby, after forming the insulationlayer 14 and the wiring 8 embedded therein, the insulation layer 14 inthe pixel region 4 is thinned and formed as a stepped construction, andthereafter the on-chip lens 19 is formed in the pixel region 4.Therefore, the insulation layer portion that is to be used for theformation of the wiring 8 does not remain in the pixel region 4 as athick film, and the distance between the on-chip lens 19 andlight-receiving face A can be made smaller.

Thus, according to the present first embodiment, in the rear-projectiontype of solid-state imaging device 1-1 that has a wiring 8 provided inthe periphery region 7 on the outer side of the pixel region 4, thepattern accuracy of the wiring 8 can be secured, while reducing thedistance between the on-chip lens 19 and light receiving face A, therebyimproving the light reception properties of the photoelectric converters20. Specifically, the distance between the light receiving face A andthe lower face of the color filter 18 can be set to approximately 600nm. Thus, optical properties, such as attenuation of incident light asto the photoelectric converters 20, and deterioration of color mixingfrom light leaking into adjacent pixels in the case of diagonal incidentlight, can be improved. Note that the present first embodiment can beapplied to a configuration that does not provide a blocking film 16. Inthis case, the distance between the light receiving face A and colorfilter 18 can be neared to approximately 300 nm, and shading and colormixing when the incident light angle is increased can be greatlyimproved.

Also, in the manufacturing method according to the first embodiment, asdescribed using FIG. 6B, in the case of forming a stepped constructionin the insulation layer 14, the etching is stopped with theetching-stopping film 14-3, after which the conditions are changed so asto etch the etching stopping film 14-3. Thus, a reflection preventingfilm 14-1 and interface level suppression film 14-2 can remain on thelight receiving face A in the pixel region 4. Consequently, stabilizedlight-receiving properties and dark current preventing effects can beobtained. Also, the light receiving face A can be favorably maintainedwithout etching damage.

Second Embodiment

Configuration of Solid-State Imaging Device

Example of Providing Insulation layer with Stepped Construction,Covering Insulating Pattern with Insulating Film

FIG. 7 is a principal portion cross-sectional diagram showing aconfiguration of a solid-state imaging device 1-2 according to a secondembodiment, and is a cross-sectional diagram of the border vicinitybetween the pixel region 4 and periphery region 7 in FIG. 1. Theconfiguration of the solid-state imaging device 1-2 according to thesecond embodiment will be described below, based on the principalportion cross-sectional diagram herein.

The solid-state imaging device 1-2 according to the second embodimentshown in FIG. 7 differs from the solid-state imaging device according tothe first embodiment described using FIG. 2 in having a layerconstruction of the insulation layer 41 that has a stepped construction,and other configurations are similar to the first embodiment.

That is to say, the insulation layer 41 has a three-layer constructionof an insulating pattern in the periphery region 7, wherein for examplea silicon oxide film 41-1, silicon nitride film 41-2, and a capping film41-3 made of silicon nitride are layered in this order from the lightreceiving face A side. Also, the insulation layer 41 has a reflectionpreventing film 41-4 and interface level suppressing film 41-5 in thepixel region 4 and periphery region 7, in the state of covering theinsulating pattern of such a three-layer construction.

The insulation layer 41 with such a five-layer construction has atwo-layer construction in the pixel region 4, of the reflectionpreventing film 41-4 and interface level suppressing film 41-5.Conversely in the periphery region 7, there is a five-layer constructionof the silicon oxide film 41-1, silicon nitride film 41-2, a cappingfilm 41-3, reflection preventing film 41-4, and interface levelsuppressing film 41-5.

In the thick film portion in the periphery region 7 of the insulationlayer 41 having such a layered construction, the lower layers of thesilicon oxide film 41-1 and silicon nitride film 41-2 become groovedfilms, and a wiring groove is formed therein to house the wiring 8.Also, the through via 23 provided through the sensor substrate 2 isconfigured so as to be connected to the wiring 8.

On the lower portion of the stepped on the insulation layer 41, ablocking film 16 is provided above the reflection preventing film 41-4and interface level suppressing film 41-5, which cover the insulatingpattern. The blocking film 6 herein is similar to that of the firstembodiment, and is provided in a state of being grounded to the sensorsubstrate 2 in the opening provided in the insulation layer 41.

Manufacturing Method of Solid-State Imaging Device

Next, a manufacturing method of a solid-state imaging device 1-2 havingthe above-described configuration will be described based on thecross-sectional process diagrams in FIGS. 8 through 10.

FIG. 8A

First, as shown in FIG. 8A, the sensor substrate 2 and circuit substrateare bonded together, and the light receiving face A side of the sensorsubstrate 2 is caused to be thinner as appropriate; up to this point issimilar to the descriptions using FIG. 3A in the first embodiment.Thereafter, the silicon oxide film 41-1 and silicon nitride film 41-2are formed on top of the light receiving face A of the sensor substrate2, in this order.

FIG. 8B

Next, as shown in FIG. 8B, a wiring groove 8 a is formed in the siliconoxide film 41-1 and silicon nitride film 41-2 in the periphery region 7of the sensor substrate 2. In this event, the silicon nitride film 41-2is etched, using the resist pattern omitted from the diagram herein as amask, and further etches the silicon oxide film 41-1. In the etchingherein, the front face layer of the sensor substrate 2 of a furtherlower layer may be etched. After the etching has ended, the resistpattern is removed.

FIG. 8C

Next, as shown in FIG. 8C, connecting holes 23 a in depths as applicableare formed on the floor portion of the wiring groove 8 a. The connectingholes 23 a herein are similar to those in the first embodiment, and areformed in various depths reaching the top of the embedded wiring 27 orthe embedded wiring 37 provided on the front face side of the sensorsubstrate 2. Subsequently, procedures similar to the proceduresdescribed using FIGS. 5A through 5C in the first embodiment areperformed.

FIG. 9A

As shown above with reference to FIG. 9A, a separating insulating film24 in a layered construction is formed on the inner walls of the wiringgrooves 8 a and connecting holes 23 a, and the inner portions herein arefilled in with copper (Cu) so as to be integrated, and the wiring 8 andthrough via 23 that are connected to the embedded wiring 27 or embeddedwiring 37 are formed.

FIG. 9B

Subsequently, as shown in FIG. 9B, a capping film 14-3 that has adispersion preventing effect as to the copper (Cu) making up the wiring8 is formed in the state of covering the wiring 8 and silicon nitridefilm 41-2. As a capping film 41-3, for example the silicon nitride filmis formed in a film thickness of 70 nm. Thus, the three layers of thesilicon oxide film 41-1, silicon nitride film 41-2, and capping film41-3 are layered onto the light receiving face A of the sensor substrate2.

Next, portions of the three-layer layered film that correspond to thepixel region 4 are selectively removed by etching in the peripheryregion 7. Thus, an insulating pattern B is formed on the light receivingface A that corresponds to the periphery region 7, by patterning thethree-layer layered film. In this event, using the resist patternomitted from the diagram herein as a mask, the capping film 41-3 made ofsilicon nitride and the silicon nitride film 41-2 are etched, andfurther, the etching conditions are changed and the silicon oxide film41-1 is etched. In etching the silicon oxide film 41-1, by performingwet etching, damage to the sensor substrate 2 is suppressed and thelight receiving face A of the pixel region 4 is exposed.

FIG. 10A

Subsequently, as shown in FIG. 10A, for example a reflection preventingfilm 41-4 made of hafnium oxide (HfO₂) and an interface levelsuppression film 41-5 made of silicon oxide (SiO₂) are formed, in thisorder, on the light receiving face A of the sensor substrate 2, in thestate of covering the insulation pattern B in the periphery region 7.Thus, an insulation layer 41, made of the insulation pattern B and thereflection preventing film 41-4 and interface level suppression film41-5 covering this, is formed on the light receiving face A.

The insulation layer 41 has a stepped construction, wherein the filmthickness of the pixel region 4 is thinner than the film thickness ofthe periphery region 7, and the pixel region 4 has a thinned cavityconstruction. In such a state, just the reflection preventing film 41-4and interface level suppression film 41-5 are disposed in the pixelregion 4. On the other hand, a five-layer construction insulation layer41 portion, made of the insulating pattern B, the reflection preventingfilm 41-4, and the interface level suppression film 41-5, are disposedin the periphery region 7.

Note that the thin film portion in the insulation layer 41 may be set tohave a wide range, in a range in which there is no influence on thewiring 8, thereby preventing influence on incident light to thephotoelectric converters 20 due to the stepped form of the insulationlayer 41 worsening the unevenness in the coating of the transparent flatfilm to be formed hereafter. This is similar to the first embodiment.

FIG. 10B

Next, as shown in FIG. 10B, openings 41 a which expose the sensorsubstrate 2 are formed on the lower portion of the step in theinsulation layer 41, and the blocking film 16 that has been grounded tothe sensor substrate 2 is formed in a pattern on the insulation layer 41via the openings 41 a in the pixel region 4. A light receiving opening16 a corresponding to each photoelectric converter 20 is provided to theblocking film 16 herein. The above process is performed using proceduresthat are similar to the procedures described with reference to FIG. 6Cin the first embodiment. Also, such a blocking film 16 may be removed onthe upper portions of the step of the insulation layer 41, and may be ina form that widely covers the lower portions of the step, and thus, thestepped form in the insulation layer 41 can be reduced over a widerange. This is also similar to the first embodiment.

FIG. 7

Subsequent to the above, as shown in FIG. 7, a transparent protectivefilm 17 made of a material having light permeability is formed in astate of covering the blocking film 16, with a coating method such as aspin-coating method. Next, color filters 18 in colors corresponding tothe photoelectric converters 20 are formed on the transparent protectivefilm 17, and further, on-chip lenses 19 that correspond to thephotoelectric converters are formed thereupon. Also, the circuitsubstrate 9 is caused to be thinner, by polishing the exposed face ofthe circuit substrate 9, and the via 33 is exposed so as to become athrough via 33. Subsequently, the protective film 9 c is formed on topof the circuit substrate 9 in a state of covering the through via 33,and a pad opening 33 a that exposes the through via 33 is formed,thereby completing the solid-state imaging device 1-2.

Advantages of Second Embodiment

The solid-state imaging device 1-2 in the configuration described above,similar to the solid-state imaging device according to the firstembodiment, is a rear-projection type that provides wiring 8 to theperiphery region 7, provides an insulation layer 41 having a thin filmstepped construction in the pixel region 4 on the light receiving faceA, and provides an on-chip lens 19 thereupon. Accordingly, similar tothe first embodiment, the pattern accuracy of the wiring 8 can besecured, while reducing the distance between the on-chip lens 19 andlight receiving face A, and improving the light reception properties bythe photoelectric converters 20.

Third Embodiment

Configuration of Solid-State Imaging Device

Example of Providing Embedded Wiring with Stepped Insulation Layer andSensor Substrate Etched Back

FIG. 11 is a principal portion cross-sectional diagram illustrating aconfiguration of a solid-state imaging device 1-3 according to a thirdembodiment, and is a cross-sectional diagram of the border vicinitybetween the pixel region 4 and periphery region 7 in FIG. 1. Aconfiguration of the solid-state imaging device 1-3 according to thethird embodiment will be described based on the principal portioncross-section herein will be described.

The portions that the solid-state imaging device 1-3 according to thethird embodiment shown in FIG. 11 differs from the solid-state imagingdevice according to the first embodiment described with reference toFIG. 2 is in the layer construction of the insulation layer 43 which hasa stepped construction, and in the embedded portion of the wiring 8, andthe other configurations are similar to that of the first embodiment.

That is to say, the insulation layer 43 is a four-layer construction ofa reflection preventing film 43-1, interface level suppressing film43-2, etching stopping film 43-3, and capping film 43-4. This four-layerconstruction insulation layer 43 is formed in a thin two-layerconstruction of the reflection preventing film 43-1 and interface levelsuppressing film 43-2 in the pixel region 4, whereby the configurationis a stepped construction wherein the film thickness in the pixel region4 is thinner than the film thickness of the periphery region 7.

In the thick film portion in the periphery region 7 of the insulationlayer 43 that is in a layered construction as described above, wiringgrooves to house the wiring 8 are formed on the etching stopping film43-3, interface level suppression film 43-2, reflection preventing film43-1, and the front face layer of the sensor substrate 2, which arelayers lower than the capping film 43-4. That is to say, wiring groovesformed by etching are formed also on the front face layer of the sensorsubstrate 2, and the wiring 8 is embedded in the wiring grooves. Also,the through via 23 provided through the sensor substrate 2 are in theconfiguration connected to the wiring 8.

Manufacturing Method of Solid-State Imaging Device

Next, a manufacturing method of the solid-state imaging device 1-3configured as described above will be described, with reference to thecross-sectional process diagrams in FIGS. 12 through 13.

FIG. 12A

First, as shown in FIG. 12A, the sensor substrate 2 and circuitsubstrate are bonded together, and the light receiving face A side ofthe sensor substrate 2 is thinned as appropriate. Up to this point isperformed similar to the descriptions of the first embodiment withreference to FIG. 3A. Thereafter, on the light receiving face A of thesensor substrate 2, for example a reflection preventing film 43-1 madeof hafnium oxide (HfO₂), interface level suppression film 43-2 made ofsilicon oxide (SiO₂), and etching stopping film 43-3 made of siliconnitride (SiN) will be layered in this order. The three layers herein areformed as a film which makes up a portion of the insulation layer (43)that has the above-described stepped construction.

Subsequently, in the periphery region 7 of the sensor substrate 2,wiring grooves 8 a′ are formed on the reflection preventing film 43-1,interface level suppressing film 43-2, etching stopping film 43-3, andfront face layer of the sensor substrate 2. In this event, using theresist pattern omitted in the diagram herein as a mask, from the etchingstopping film 43-3 to the front face layer of the sensor substrate 2 isetched. Upon etching being ended, the resist pattern is removed.

FIG. 12B

Next, as shown in FIG. 12B, connecting holes 23 a in depths asappropriate are formed in the wiring grooves 8 a′. The connecting holes23 a are similar to the first embodiment, and are formed in variousdepths that reach the upper portion of the embedded wiring 27 orembedded wiring 37 which are provided on the front face side of thesensor substrate 2. Thereafter, procedures similar to the proceduresdescribed in the first embodiment with reference to FIGS. 5A through 5Care performed.

FIG. 12C

Thus, as shown in FIG. 12C, a separating insulating film 24 in a layeredconstruction is formed on the inner walls of the wiring grooves 8 a′ andconnecting holes 23 a, the inner portions herein are filled in withcopper (Cu) so as to be integrated, and the wiring 8 and through via 23that are connecting to the embedded wiring 27 or embedded wiring 37 areformed.

FIG. 13A

Subsequently, as shown in FIG. 13A, a capping film 43-4 having adispersion preventing effect as to the copper (Cu) making up the wiring8 is formed in a state of covering the wiring 8 and etching stoppingfilm 43-3. Now, as a capping film, a silicon nitride film is formed in afilm thickness of 70 nm. Thus, a four-layer construction of insulationlayer 43 is formed on the light receiving face A of the sensor substrate2, layering in the order of the reflection preventing film 43-1,interface level suppressing film 43-2, etching stopping film 43-3, andcapping film 43-4. Note that a silicon oxide film may further be formedas appropriate on top of the uppermost layer which is the capping film43-4 made of silicon nitride.

Upon forming the layered construction insulation layer 43 and wiring 8as described above, the portions of the insulation layer 43corresponding to the pixel region 4 are selectively made thin, therebyforming the insulation layer 43 in a stepped construction. In thisevent, using the resist pattern, which is omitted in the diagram herein,as a mask, the capping film 43-4 and etching stopping film 43-3 made ofsilicon nitride (SiN) are etched.

Thus, the insulation layer 43, which has a stepped construction whereinthe film thickness in the pixel region 4 is thinner than the filmthickness in the periphery region 7, and which has a cavity constructionthat is thinned in the pixel region 4, is provided on the lightreceiving face A of the sensor substrate 2. In such a state, just thereflection preventing film 43-1 and interface level suppression film43-2 remain in the pixel region 4. On the other hand, the four-layerconstruction insulation layer 43 remains without change in the peripheryregion 7.

Note that the thin film portion in the insulation layer 43 may be set tohave a wide range, in a range in which there is no influence on thewiring 8, thereby preventing influence on incident light to thephotoelectric converters 20 due to the stepped form of the insulationlayer 43 worsening the unevenness in the coating of the transparent flatfilm to be formed hereafter. This is similar to the first embodiment.

FIG. 13B

Next, as shown in FIG. 13B, openings 43 a which expose the sensorsubstrate 2 are formed on the lower portion of the step in theinsulation layer 43, and the blocking film 16 that has been grounded tothe sensor substrate 2 is formed in a pattern on the insulation layer 43via the openings 43 a in the pixel region 4. A light receiving opening16 a corresponding to each photoelectric converter 20 is provided tothis blocking film 16. The above process is performed using proceduresthat are similar to the procedures described with reference to FIG. 6Cin the first embodiment. Also, such a blocking film 16 may be removed onthe upper portions of the step of the insulation layer 43, and may be ina form that widely covers the lower portions of the step, and thus, thestepped form in the insulation layer 43 can be reduced over a widerange. This is also similar to the first embodiment.

FIG. 11

Subsequent to the above, as shown in FIG. 11, a transparent protectivefilm 17 made of a material having light permeability is formed in astate of covering the blocking film 16, with a coating method such as aspin-coating method. Next, color filters 18 in colors corresponding tothe photoelectric converters 20 are formed on the transparent protectivefilm 17, and further, on-chip lenses 19 that correspond to thephotoelectric converters are formed thereupon. Also, the circuitsubstrate 9 is caused to be thinner, by polishing the exposed face ofthe circuit substrate 9, and the via 33 is exposed so as to become athrough via 33. Subsequently, the protective film 9 c is formed on topof the circuit substrate 9 in a state of covering the through via 33,and a pad opening 33 a that exposes the through via 33 is formed,thereby completing the solid-state imaging device 1-3.

Advantages of Third Embodiment

The solid-state imaging device 1-3 in the configuration described above,similar to the solid-state imaging device according to the firstembodiment, is a rear-projection type that provides wiring 8 to theperiphery region 7, provides an insulation layer 43 having a thin filmstepped construction in the pixel region 4 on the light receiving faceA, and provides an on-chip lens 19 thereupon. Accordingly, similar tothe first embodiment, the pattern accuracy of the wiring 8 can besecured, while reducing the distance between the on-chip lens 19 andlight receiving face A, and improving the light reception properties bythe photoelectric converters 20. Also, similar to the first embodiment,the light receiving face A can be favorably maintained without etchingdamage.

Note that according to the present third embodiment, a configuration isdescribed which provides a wiring groove 8 a′, into which the wiring 8is embedded, on the sensor substrate 2 and the lower portion of theinsulation layer 43. However, the wiring grooves 8 a′ may be formed justin the sensor substrate 2, and the wiring 8 completely embedded as tothe sensor substrate. In this case also, similar advantages can beobtained by having a stepped construction wherein the insulation layer43 is secured at an appropriate film thickness to cover the wiring 8 inthe periphery region 7, and a film thickness that is thinned to bethinner than this is used in the pixel region 4.

Fourth Embodiment

Configuration of Solid-State Imaging Device

Example of Providing Insulation Layer and Layered Wiring in a SteppedConstruction

FIG. 14 is a principal portion cross-sectional diagram showing theconfiguration of the solid-state imaging device 1-4 according to thefourth embodiment, and is a cross-sectional diagram near the borderbetween the pixel region 4 and periphery region 7 in FIG. 1. Aconfiguration of the solid-state imaging device 1-4 according to thefourth embodiment based on the principal portion cross-sectional diagramherein will be described.

The solid-state imaging device 1-4 according to the fourth embodimentshown in FIG. 14 differs from the solid-state imaging device accordingto the first embodiment described with reference to FIG. 2 in having alayer construction of an insulation layer 45 which has a steppedconstruction, and in a wiring 47, and the other configurations aresimilar to the first embodiment.

That is to say, the insulation layer 45 has a five-layer constructionmade of a reflection preventing film 45-1, interface level suppress film45-2, etching stopping film 45-3, capping film 45-4, and an insulatingfilm 45-5 made of silicon oxide. This five-layer construction insulationlayer 45 is formed in a two-layer construction of the reflectionpreventing film 45-1 and interface level suppress film 45-2 in the pixelregion 4, whereby the configuration is a stepped construction whereinthe film thickness in the pixel region 4 is thinner than the filmthickness in the periphery region 7.

At the thick film portion in the periphery region 7 of the insulationlayer 45 made in a layered construction as described above, the throughvia 23 provided through the sensor substrate 2 is expended to thesurface of the etching stopping film 45-3.

Also, the wiring 47 is formed in a pattern on the insulation layer 45via the openings 43 a in the periphery region 7. The wiring 47 is madeof an etchable conductive material such as aluminum, for example, andconnects the upper layer of the insulation layer 45 to the through via23 via the connecting holes provided in the capping film 45-4 andinter-layer film 45-5. This wiring 47 is covered with an insulatingprotective film 49.

Manufacturing Method of Solid-State Imaging Device

Next, a manufacturing method according to the solid-state imaging device1-4 in the configuration described above will be described based on thecross-sectional process diagrams in FIGS. 15 and 16.

FIG. 15A

First, as shown in FIG. 15A, the sensor substrate 2 and circuitsubstrate are bonded together, and the light receiving face A side ofthe sensor substrate 2 is thinned as appropriate. Up to this point isperformed similar to the descriptions of the first embodiment withreference to FIG. 3A. Thereafter, on the light receiving face A of thesensor substrate 2, for example a reflection preventing film 45-1 madeof hafnium oxide (HfO₂), interface level suppression film 45-2 made ofsilicon oxide (SiO₂), and etching stopping film 45-3 made of siliconnitride (SiN) will be layered in this order. The three layers herein areformed as a film which makes up a portion of the insulation layer (45)that has the above-described stepped construction.

Subsequently, in the periphery region 7 of the sensor substrate 2,connecting holes 23 a in depths as appropriate are formed in the etchingstopping film 45-3, interface level suppression film 45-2, reflectionpreventing film 45-1, sensor substrate 2, and inter-layer insulatingfilm which makes up the wiring layer 2 a. The connecting holes 23 a aresimilar to the first embodiment, and are formed in various depths thatreach the upper portions of the embedded wiring 27 or embedded wiring37.

FIG. 15B

As shown in FIG. 15B, a separating insulating film 24 in a layeredconfiguration is formed on the inner walls of the connecting holes 23 a,and by filling the inner portions thereof with copper (Cu), the throughvias 23 connected to the embedded wiring 27 and embedded wiring 37 areformed within the connecting holes 23 a. The separating insulating film24 and through via 23 can be formed with procedures similar to theprocedures described with reference to FIGS. 5A through 5C according tothe first embodiment.

FIG. 15C

Next, as shown in FIG. 15C, as a capping film 45-4 that has a dispersionpreventing effect as to the copper (Cu) making up the through via 23,for example a silicon nitride film in a film thickness of 70 nm isformed in a state of covering the through via 23 and etching stoppingfilm 45-3. Further, a silicon oxide film is formed thereupon as aninter-layer film 45-5. Thus, an insulation layer 45 in a five-layerconstruction is formed on the light receiving face A of the sensorsubstrate 2, in a layered manner in the order of a reflection preventingfilm 45-1, interface level suppressing film 45-2, etching stopping film45-3, capping film 45-4, and inter-layer film 45-5.

FIG. 16A

Subsequently, as shown in FIG. 16A, in the periphery region 7,connecting holes 23 b that reach the through vias 23 are formed in theinter-layer film 45-5 and capping film 45-4. Thereafter, wiring 47 thatis connected to the through via 23 via the connecting holes 23 b isformed on the inter-layer film 45-5. In this event, a film made ofconductive material such as aluminum is formed on the inter-layer film45-5 with a sputtering method, and next, the resist pattern formedthereupon is used as a mask to etch the conductive material film therebyforming the wiring 47 by patterning the conductive material film. Afterthis, a protective film 49 that covers the wiring 47 is formed on theinter-layer film 45-5 as appropriate. Note that the protective film 49also can be a film that makes up the insulation layer 45.

FIG. 16B

Next, as shown in FIG. 16B, the portions of the insulation layer 45corresponding to the pixel region 4 are selectively made thin, therebyforming the insulation layer 45 in a stepped construction. In thisevent, using the resist pattern, which is omitted in the diagram herein,as a mask, the protective film 49, inter-layer film 45-5, capping film45-4 and etching stopping film 45-3 are etched.

Thus, the insulation layer 45, which has a stepped construction whereinthe film thickness in the pixel region 4 is thinner than the filmthickness in the periphery region 7, and which has a cavityconfiguration that is thinned in the pixel region 4, is provided on thelight receiving face A of the sensor substrate 2. In such a state, justthe reflection preventing film 43-1 and interface level suppression film43-2 remain in the pixel region 4. On the other hand, the five-layerconstruction insulation layer 45 and protective film 49 remain withoutchange in the periphery region 7.

Note that the thin film portion in the insulation layer 45 may be set tohave a wide range, in a range in which there is no influence on thewiring 47, thereby preventing influence on incident light to thephotoelectric converters 20 due to the stepped form of the insulationlayer 45 worsening the unevenness in the coating of the transparent flatfilm to be formed hereafter. This is similar to the first embodiment.

FIG. 16C

Next, as shown in FIG. 16C, openings 45 a which expose the sensorsubstrate 2 are formed on the lower portion of the step in theinsulation layer 45, and the blocking film 16 that has been grounded tothe sensor substrate 2 is formed in a pattern on the insulation layer 45via the openings 45 a in the pixel region 4. A light receiving opening16 a corresponding to each photoelectric converter 20 is provided to theblocking film 16 herein. The above process is performed using proceduresthat are similar to the procedures described with reference to FIG. 6Cin the first embodiment. Also, such a blocking film 16 may be removed onthe upper portions of the step of the insulation layer 45, and may be ina form that widely covers the lower portions of the step, and thus, thestepped form in the insulation layer 45 can be reduced over a widerange. This is also similar to the first embodiment.

FIG. 14

Subsequent to the above, as shown in FIG. 14, a transparent protectivefilm 17 made of a material having light permeability is formed in astate of covering the blocking film 16, with a coating method such as aspin-coating method. Next, color filters 18 in colors corresponding tothe photoelectric converters 20 are formed on the transparent protectivefilm 17 and further, on-chip lenses 19 that correspond to thephotoelectric converters are formed thereupon. Also, the circuitsubstrate 9 is caused to be thinner, by polishing the exposed face ofthe circuit substrate 9, and the via 33 is exposed so as to become athrough via 33. Subsequently, the protective film 9 c is formed on topof the circuit substrate 9 in a state of covering the through via 33,and a pad opening 33 a that exposes the through via 33 is formed.Further, a pad opening that exposes the wiring 47, which is omitted inthe diagram herein, is formed on the wiring 47 made of aluminum or thelike, and the solid-state imaging device 1-4 is completed.

Advantages of Fourth Embodiment

The solid-state imaging device 1-4 in the configuration described above,similar to the solid-state imaging device according to the firstembodiment, is a rear-projection type that provides wiring 47 to theperiphery region 7, provides an insulation layer 45 having a thin filmstepped construction in the pixel region 4 on the light receiving faceA, and provides an on-chip lens 19 thereupon. Accordingly, theinsulation layer 45 of a film thickness appropriate to the configurationof the wiring 47 can remain in the periphery region 7, while reducingthe distance between the on-chip lens 19 and light receiving face A, andimproving the light reception properties by the photoelectric converters20. Also similar to the first embodiment, the light receiving face A canbe favorably maintained without etching damage.

Fifth Embodiment

Example of Providing a Shared Connection to the Wiring Connectionswithin the Sensor Substrate

FIG. 17 is a principal portion cross-section diagram showing theconfiguration of a solid-state imaging device 1-5 according to a fifthembodiment, and is a cross-section diagram near the border of the pixelregion 4 and periphery region 7 in FIG. 1. The configuration of thesolid-state imaging device 1-5 according to the fifth embodiment will bedescribed below, based on the principal portion cross-sectional diagramherein.

The solid-state imaging device 1-5 of a modification shown in FIG. 17differs from the solid-state imaging device according to the firstembodiment described with reference to FIG. 2 in the configuration of athrough via 51 and a layer construction of the insulation layer 53, andother configurations thereof are similar to the first embodiment.

That is to say, the through via 51 is a so-called shared connectionwhich connects the embedded wiring 27 provided to the wiring layer 2 aand the embedded wiring 37 provided to the wiring layer 9 a, forexample, and is provided as wiring that connects the embedded wiring 27and embedded wiring 37 herein. As such wiring, the through via 51 formedin an integrated manner is connected to the embedded wiring 27 andembedded wiring 37 on floor faces having different heights. Also, thethrough via 51 protrudes up through the light receiving face A of thesensor substrate 2, and the protruding portions are embedded in aninsulation layer 53.

This through via 51 that also serves as wiring is made of an embeddedconductive material via the separating insulating film 24, passingthrough the sensor substrate 2 from the insulating layer 53, furtherwithin the connecting holes 51 a provided to the wiring layer 2 a.

The insulation layer 53 having a stepped construction wherein the filmthickness of the pixel region 4 is thinner than the film thickness ofthe periphery region 7, and the insulation layer being configured as alayering film using different insulating materials, for example, aresimilar to the first embodiment. This insulation layer 53 is afour-layer construction, for example, of a reflection preventing film53-1, interface level suppressing film 53-2, etching stopping film 53-3,and capping film 53-4, in sequence from the light receiving face A side.For example, the reflection preventing film 53-1 is made of a hafniumoxide (HfO₂) film. The interface level suppressing film 53-2 is made ofa silicon oxide film (SiO₂). The etching stopping film 53-3 is made ofsilicon nitride (SiN). Further, the capping film 53-4 is made of siliconnitride (SiN).

This four-layer insulation layer 53 is made thin in a two-layerconstruction of the reflection preventing film 53-1 and interface levelsuppressing film 53-2, in the pixel region 4. In the thick film portionsof the insulation layer 53 in the periphery region 7, a through via 51is extended from the etching stopping film 53-3 which is second from thetop layer, to the connecting hole 51 a provided on the lower layer, alsoas the above-described wiring.

Manufacturing of a solid-state imaging device 1-5 having such aconfiguration is performed, in forming the connecting holes 23 adescribed with reference to FIG. 15A according to the fourth embodiment,by patterning so that one connecting hole 51 a is disposed on the upperportion of both the embedded wiring 27 and the embedded wiring 37. Next,by performing procedures similar to the procedures described withreference to FIG. 15B, the through via 51 filled in with copper (Cu) viathe separating insulating film 24 within the connecting hole 15 a isformed as the wiring connected to the embedded wiring 27 and theembedded wiring 37. Next, by forming the capping film 53-4 and byselectively removing the capping film 53-4 and etching stopping film53-3 in the pixel region 4, the insulation layer 53 has a steppedconstruction. After the above described process, procedures similar tothose described according to other embodiments are performed, wherebythe blocking film 16 having a light receiving opening 16 a, atransparent protective film 17, color filter 18, and on-chip lens 19,are formed. Also, the circuit substrate 9 is thinned to expose the via33 so as to make a through via 33, a protective film 9 c is formed onthe circuit substrate 9, and a pad opening 33 a to expose the throughvia 33 are formed, whereby the solid-state imaging device 1-5 iscompleted.

Advantages of Fifth Embodiment

The solid-state imaging device 1-5 in the configuration described above,similar to the solid-state imaging device according to the firstembodiment, is a rear-projection type that provides a through via 51serving as wiring to the periphery region 7, provides an insulationlayer 53 having a thin film stepped construction in the pixel region 4on the light receiving face A, and provides an on-chip lens 19thereupon. Accordingly, the insulation layer 53 of a film thicknessappropriate to the configuration of the through via 51 serving as wiringcan remain in the periphery region 7, while reducing the distancebetween the on-chip lens 19 and light receiving face A, and improvingthe light reception properties by the photoelectric converters 20. Alsosimilar to the first embodiment, the light receiving face A can befavorably maintained without etching damage.

Note that according to the first through fifth embodiments, as anexample of a rear-projection type solid-state imaging device,configurations that apply the present technology to a three-dimensionalconstruction of a solid-state imaging device has been described.However, the present technology can be widely used in rear-projectiontype solid-state imaging devices, and is not limited to athree-dimensional construction. Also, the insulation layer having astepped construction is not limited to the layered constructiondescribed according to the embodiments, and layered constructions thatare applicable to the improvement in forming wiring and improving lightreception properties.

Sixth Embodiment

Principal Portion Configuration of Solid-State Imaging Device 1

FIGS. 18-21 are diagrams illustrating principal portion configurationsof a solid-state imaging device according to a sixth embodiment. FIG. 18is an upper-face diagram and illustrates a face on the sensor substrate100 side. Also, FIGS. 19 and 20 are cross-sectional diagrams. FIG. 19illustrates a cross-section taken along line XIX-XIX in FIG. 18.Conversely, FIG. 20 illustrates a cross-section taken along line XX-XXin FIG. 18. FIG. 21 shows a circuit configuration of a pixel P.

Overview of Upper Face Configuration

As shown in FIG. 18, the solid-state imaging device 1 provides a chipregion CA and scribe region LA on a face (xy face). As shown in FIG. 18,the chip region CA is in a rectangular shape that has been segmented inthe horizontal direction x and the vertical direction y, and includes apixel region PA. In addition, the chip region CA includes a peripheryregion SA. In the chip region CA, the pixel region PA has a rectangularshape, and multiple pixels P are arrayed in each of the horizontaldirection x and vertical direction y and disposed thereon, as shown inFIG. 18. In the chip region CA, the periphery region SA is positioned inthe periphery of the pixel region PA, as shown in FIG. 18. A pad unitPAD and a periphery circuit unit SK are provided to the periphery regionSA, as shown in FIG. 18.

The scribe region LA is positioned so as to surround the periphery ofthe chip region CA, as shown in FIG. 18. Now, the scribe region LAincludes portions extending in each of the horizontal direction x andthe vertical direction y, and is provided so as to draw a rectanglearound the chip region CA.

Multiple chip regions CA are arrayed and provided to a wafer (unshown)prior to dicing, and the scribe region LA is provided in grid formbetween the multiple chip regions CA thereof. In the scribe region LA, ablade is applied and dicing is performed, and the above-described chipregion CA is divided into the solid-state imaging device 1.

Overview of Cross-Sectional Configuration

As shown in FIGS. 19 and 20, the solid-state imaging device 1 includes asensor substrate 100 and logic substrate 200, which are bonded togetherfacing each other. As shown in FIGS. 19 and 20, the sensor substrate 100includes a semiconductor substrate 101. The semiconductor substrate 101is made of single-crystal silicon, for example.

As shown in FIGS. 19 and 20, the sensor substrate 100 has a wiring layer110 and insulating film 120 provided, in sequence thereof, to the frontface (bottom face) of the semiconductor substrate 101 that faces thelogic substrate 200. The wiring layer 110 and insulating film 120 eachare provided across the entire front face (bottom face) of thesemiconductor substrate 101.

As shown in FIG. 19, photodiodes 21 are provided within the innerportion of the semiconductor substrate 101 in the pixel region PA. Asshown in FIGS. 19 and 20, an insulating film 102 is provided to the backface (upper face) of the semiconductor substrate 101 in the sensorsubstrate 100. The insulating film 102 is provided across the entireback face (upper face) of the semiconductor substrate 101.

Also, as shown in FIGS. 19 and 20, a passivation film 401, blocking film500, flat film 501 are provided to the back face (upper face) of thesemiconductor substrate 101, via the insulating film 102. Also, as shownin FIG. 19, in the pixel region PA, a color filter CF and on-chip lensOCL are provided on the flat film 501. Conversely, in the pad portionPAD, a shown in FIG. 20, a lens material film 601 is provided on theflat film 501.

While omitted from these drawings, in the sensor substrate 100, asemiconductor circuit device (unshown) is provided on the lower faceside to which the wiring layer 100 is provided. Specifically, in thepixel region PA, the semiconductor circuit device (unshown) is providedso as to configure the pixel transistor Tr shown in FIG. 21. Also, inthe periphery region SA, a semiconductor circuit device (unshown) isprovided so as to configure a vertical driving circuit 3 and timinggenerator 8, for example.

As shown in FIGS. 19 and 20, the logic circuit 200 includes asemiconductor substrate 201. The semiconductor substrate 201 is made ofsingle-crystal silicon, for example. The logic substrate 200 has thesemiconductor substrate 201 facing the semiconductor substrate 101 ofthe sensor substrate 100. The semiconductor substrate 201 of the logicsubstrate 200 also functions as a supporting substrate, whereby theoverall strength of the solid-state imaging device 1 is secured.

As shown in FIGS. 19 and 20, the logic substrate 200 has a wiring layer210 and insulating film 220 provided, in sequence, on the front face(upper face) of the side of the semiconductor substrate 201 facing thesensor substrate. The wiring layer 210 and insulating film 220 are bothprovided across the entire front face (upper face) of the side of thesemiconductor substrate 201.

While omitted from the drawings, a semiconductor circuit device(unshown) such as a MOS transistor is provided to the front face (upperface) side of the semiconductor substrate 201. The semiconductor circuitdevice (unshown) is provided, for example, so as to configure a columncircuit 4, horizontal driving circuit 5, and external output circuit 7.

The solid-state imaging device 1, as shown in FIGS. 19 and 20, has theinsulating film 120 of the sensor substrate 100 and the insulating film220 of the logic substrate 200 joined together with a joining face SM,whereby the sensor substrate 100 and logic substrate 200 are both bondedtogether.

As shown in FIG. 19, the solid-state imaging device 1 is configured sothat the photodiodes 21 receive the incident light H input from the backface (upper face) that is on the opposite side from the front face(lower face) side of the semiconductor substrate 101 of the sensorsubstrate 100 to which the wiring layer 110 is provided. That is to say,the solid-state imaging device 1 is a “back face projection type CMOSimage sensor”.

Detailed Configuration of Parts

Details of the parts making up the solid-state imaging device 1 will bedescribed, in sequence.

(a) Photodiode 21

As shown in FIG. 19, photodiodes 21 are provided in the pixel region PA,corresponding to each of the multiple pixels P. The photodiodes 21 areprovided to the semiconductor substrate 101, the thickness of which hasbeen thinned to 1 to 30 μm for example, in the sensor substrate 100. Thephotodiodes 21 are formed so as to generate and accumulate signal loadby receiving the incident light H that is incident as a subject imageand performing photoelectric conversion.

Now, as shown in FIG. 19, parts such as a color filter CF, micro lensML, and so forth are provided above the photodiodes 21 which is on theback face (upper face) of the semiconductor substrate 101. Therefore,the photodiodes 21 receive the incident light H that is incident via theparts herein, in sequence, with a light receiving face JS.

The photodiode 21 includes an n-type load accumulating region (unshown)which accumulates signal load (electrons), and the n-type loadaccumulating region (unshown) is provided to a p-type semiconductorregion (unshown) on the semiconductor substrate 101. In the n-type loadaccumulating region, a p-type semiconductor region (unshown) having ahigh concentration of impurities is provided as a hole accumulationlayer on the front face side of the semiconductor substrate 101. That isto say, the photodiodes 21 are formed in a HAD (Hole Accumulation Diode)construction.

As shown in FIG. 21, each photodiode 21 is grounded with an anode; theaccumulated signal load is read out with a pixel transistor Tr, andoutput as an electrical signal to the vertical signal line 27.

(b) Pixel Transistor Tr

A pixel transistor Tr is provided corresponding to each of the multiplepixels P in the pixel region PA, as described above. As shown in FIG.21, the pixel transistor Tr includes a transfer transistor 22,amplifying transistor 23, selecting transistor 24, and reset transistor25, and for each pixel P, outputs signal load as an electrical signalfrom the photodiode 21.

As described above, in FIG. 19 the pixel transistor Tr is omitted fromthe diagram, but the pixel transistor Tr is provided on the front face(lower face) of the semiconductor substrate 101. Specifically, thetransistors 22 through 25 that make up the pixel transistor Tr form anactivation region (unshown) in a region separating pixels P from eachother on the semiconductor substrate 101, and the gates are formed usingpolysilicon which includes n-type impurities.

In the pixel transistor Tr, as shown in FIG. 21, the transfer transistor22 is configured so as to transfer the signal load generated by thephotodiode 21 to the floating diffusion FD. Specifically, the transfertransistor 22 is provided between the cathode of the photodiode 21 andthe floating diffusion FD. Also, the transfer transistor 22 has atransfer line 26 electrically connected to a gate. The transfertransistor 22 transfers the signal load accumulated in the photodiode 21to the floating diffusion FD, based on the transfer signal TGtransmitted from the transfer line 26 to the gate.

In the pixel transistor Tr, as shown in FIG. 21, the amplifyingtransistor 23 is configured so as to amplify the electrical signalconverted from load to voltage in the floating diffusion FD and outputthis. Specifically, the amplifying transistor 23 has a gate that iselectrically connected to the floating diffusion FD. Also, theamplifying transistor 23 has a drain that is electrically connected to apower source supply line Vdd, and a source that is electricallyconnected to the selecting transistor 24. Upon the selecting transistor24 being selected to be in the on state, constant current is suppliedfrom a constant current source I, and the amplifying transistor 23operates as a source follower. Therefore, by a selection signal beingsupplied to the selecting transistor 24, the electrical signal convertedfrom load to voltage at the floating diffusion FD is amplified in theamplifying transistor 23.

In the pixel transistor Tr, as shown in FIG. 21, the selectingtransistor 24 is configured so as to output the electrical signal outputfrom the amplifying transistor 23 to the vertical signal line 27, basedon the selecting signal. Specifically, the selecting transistor 24 has agate connected to an address line 28 to which the selection signal issupplied. Also, in the event that a selection signal is supplied, theselecting transistor 24 is turned on, and outputs the output signalamplified by the amplifying transistor 23 to the vertical signal line27.

In the pixel transistor Tr, as shown in FIG. 21, the reset transistor 25is configured so as to reset the gate potential of the amplifyingtransistor 23. Specifically, the reset transistor 25 has a gate that iselectrically connected to the reset line 29 to which a reset signal issupplied. Also, the reset transistor 25 has a drain that is electricallyconnected to the power source supply line Vdd and a source that iselectrically connected to the floating diffusion FD. The resettransistor 25 resets the gate potential of the amplifying transistor 23to the power source voltage, based on the reset signal transmitted fromthe reset line 29, via the floating diffusion FD.

The gates of the transistors 22, 24, and 25 are connected in rowincrements made up of multiple pixels P that are arrayed in thehorizontal direction x, and the multiple pixels arrayed in the rowincrements thereof are driven simultaneously. Specifically, the pixelsare selected in sequence in the vertical direction in increments of ahorizontal line (pixel row), by the selection signal supplied by theabove-described vertical driving circuit (unshown). The transistors ofthe pixels P are controlled by the various types of timing signalsoutput from a timing generator (unshown). Thus, the output signals inthe pixels P are read out to a column circuit (unshown) for each columnof pixels P through the vertical signal line 27. The signal held in thecolumn circuit is then selected by the horizontal driving circuit(unshown), and output in sequence to the external output circuit(unshown).

(c) Wiring Layer 110 and Insulating Film 120 of Sensor Substrate 100

On the sensor substrate 100, as shown in FIGS. 19 and 20, the wiringlayer 110 is provided on the front face (lower face) of thesemiconductor substrate 101 which is on the opposite side from the backface (upper face) thereof on which parts such as the color filter CF,micro lens ML, and so forth have been provided. That is to say, on thesensor substrate 100, the wiring layer 110 is provided on the face ofthe side of the semiconductor substrate 101 facing the logic substrate(the lower face).

The wiring layer 110 includes a wiring 110H and insulating film 110Z, asshown in FIG. 19, and the wiring 110H is provided within the insulatingfilm 1102. The wiring layer 110 is a so-called multi-layer wiring layer,and is formed by an inter-layer insulating film making up the insulatingfilm 110Z, and a wiring 110H, alternately layered multiple times.

The insulating film 110Z is formed using insulating materials. Also, thewiring 110H is formed using a conductive metallic material. The wiringlayer 110 is formed by multiple layers of the wiring 110H, so as tofunction as the transfer line 26, address line 28, vertical signal line27, reset line 29, and so forth shown in FIG. 21. As shown in FIGS. 19and 20, the insulating film 120 is provided on the front face (lowerface) which is on the opposite side of the wiring layer 110 from thesemiconductor substrate 101 side.

(d) Wiring Layer 210 and Insulating Film 220 of Logic Substrate 200

On the logic substrate 200, as shown in FIGS. 19 and 20, the wiringlayer 210 is provided on the face of the side of the semiconductorsubstrate 201 facing the sensor substrate 100 (the upper face). Thewiring layer 210 includes a wiring 210H and insulating film 210Z, asshown in FIG. 19, and the wiring 210H is provided within the insulatingfilm 210Z. The wiring layer 210 is a so-called multi-layer wiring layer,and is formed by an inter-layer insulating film making up the insulatingfilm 210Z, and a wiring 210H, alternately layered multiple times.

The insulating film 210Z is formed using insulating materials. Also, thewiring 210H is formed using a conductive metallic material. The wiringlayer 210 is formed by multiple layers of the wiring 210H so as tofunction as the wiring that is electrically connected to thesemiconductor circuit device (unshown) which is provided on thesemiconductor substrate 201 of the logic substrate 200. As shown inFIGS. 19 and 20, the insulating film 220 is provided on the front face(upper face) which is on the opposite side of the wiring layer 210 fromthe semiconductor substrate 201 side.

(e) Pad Portion PAD

The pad portion PAD is provided to the periphery region SA, as shown inFIG. 18. As shown in FIG. 20, pad wirings 110P and 210P, and aconnecting conductive layer 301 are provided to the pad portion PAD. Theparts provided to the pad portion PAD will be described in sequence.

(e-1) Pad Wiring 110P and 210P

As shown in FIG. 20, a pad wiring 110P is provided to the sensorsubstrate 100 in the pad portion PAD. Also, a pad wiring 210P isprovided to the logic substrate 200 in the pad portion PAD.

The pad wiring 110P provided to the sensor substrate 110 is formedwithin the wiring layer 110, as shown in FIG. 20, similar to the otherwiring 110H. Also, the pad wiring 110P of the sensor substrate 100 isprovided further above the pad wiring 210P provided to the logicsubstrate 200, on the layered body of sensor substrate 100 and logicsubstrate 200. The pad wiring 110P of the sensor substrate 100 iselectrically connected to the other wiring 110H, and electricallyconnects between the semiconductor circuit device (unshown) provided tothe sensor substrate 100 and a device (unshown) provided outsidethereof.

The pad wiring 210P provided to the logic substrate 200 is providedwithin the insulating film 201Z, similar to the other wiring 210H makingup the wiring layer 210. The pad wiring 210P of the logic substrate 200is electrically connected to the other wiring 210H, and electricallyconnects between the semiconductor circuit device (unshown) provided tothe logic substrate 200 and a device (unshown) provided outside thereof.Also, as shown in FIG. 20, the pad wiring 110P of the sensor substrate100 and the pad wiring 210P of the logic substrate 200 are electricallyconnected with a connecting conductive layer 301.

(e-2) Connecting Conductive Layer 301

As shown in FIG. 20, a connecting conductive layer 301 is provided tothe pad portion PAD. The connecting conductive layer 301 is provided onthe upper face side of the layered body wherein the sensor substrate 100and logic substrate 200 have been bonded together.

The connecting conductive layer 301 is formed with a conductive metallicmaterial, and electrically connects the pad wiring 110P of the sensorsubstrate 100 and the pad wiring 210P of the logic substrate 200. Theconnecting conductive layer 301 is provided by sequentially layering abarrier metal layer such as tantalum (Ta) and a copper-plate layerformed by plating with copper (Cu), for example.

Now, the connecting conductive layer 301 includes a first plug 311,second plug 321, and connective wiring 331, as shown in FIG. 20. In theconnecting conductive layer 301, as shown in FIG. 20, the first plug 311is formed within a pad opening V1 which is provided above the pad wiring110P of the sensor substrate 100. Also, as shown in FIG. 20, the secondplug 321 is formed within a pad opening V2 which is provided above thepad wiring 210P of the logic substrate 200.

Specifically, each pad opening V1 and V2 are provided so as to passthrough from the upper side of the respective pad wiring 110P and 210Pto the upper face of the insulating film 102. The pad openings V1 and V2are formed so as to pass through the semiconductor substrate 101 whichis included in the sensor substrate 100. That is to say, each of thefirst plug 311 and second plug 321 are a TSV. Also, while omitted fromthe diagram, the pad openings V1 and V2 are formed so that the upperface becomes a circular shape, for example.

The pad openings V1 and V2 include upper-side opening portions V11 andV21 and lower-side opening portions V12 and V22. Each of the upper-sideopening portions V11 and V21 and lower-side opening portions V12 and V22are provided to the pad openings V1 and V2, respectively, so as to belayered in the depth direction z.

Of the multiple pad openings V1 and V2, the pad opening V1 providedabove the pad wiring 110P on the sensor substrate 110 is provided sothat the upper-side opening portion V11 passes through from the upperportion of the wiring layer 110 on the sensor substrate 100 to the upperface of the insulating film 102.

The lower-side opening portion V12 is provided so that the upper face ofthe pad wiring 110P is exposed in the pad opening V1. The side face ofthe upper-side opening portion V11 of the pad opening V1 herein iscovered with an insulating film 102, and the first plug 311 is providedso as to embed within the upper-side opening portion V11 and lower-sideopening portion V12, via the insulating film 102 thereof.

Of the multiple pad openings V1 and V2, the pad opening V2 providedabove the pad wiring 210P on the logic substrate 200 is provided so thatthe upper-side opening portion V21 passes through from the upper portionof the wiring layer 210 on the logic substrate 200 to the upper side ofthe insulating film 102. The upper-side opening portion V21 is formed inthe same flat shape, except in the point of being provided so as to bedeeper than the upper-side opening portion V11 of the other pad openingV1. That is to say, the width H21 of the upper-side opening portion V21is formed to be the same as the width H11 of the upper-side openingportion V11.

The lower-side opening portion V22 is provided so that the upper face ofthe pad wiring 210P is exposed in the pad opening V2. The lower-sideopening portion V22 is formed in the same flat shape, except in thepoint of being provided so as to be deeper than the lower-side openingportion V22 of the other pad opening V2. That is to say, the width H22of the lower-side opening portion V22 is formed to be the same as thewidth H12 of the upper-side opening portion V12.

The side face of the upper-side opening portion V21 of the pad openingV2 herein is covered with an insulating film 102, and the second plug321 is provided so as to embed within the upper-side opening portion V21and lower-side opening portion V22, via the insulating film 102 thereof.

In the connecting conductive layer 301, as shown in FIG. 20, theconnective wiring 331 is provided to the upper face side on the oppositeside from the lower face that faces the logic substrate 200 of thesensor substrate 100. As shown in FIG. 20, a trench TR is provided tothe insulating film 102 that covers the upper face of the semiconductorsubstrate 101 that is included in the sensor substrate 100. The trenchTR is provided above the multiple pad openings V1 and V2, and theconnective wiring 331 is formed so as to embed within the trench TRherein.

Now, the connective wiring 331 is provided to the upper portion of thefirst plug 311 and second plug 321 so as to link between the first plug311 and second plug 321. The connective wiring 331 is formed so as to beintegrated with the first plug 311 and second plug 321, and electricallyconnects the pad wirings 110P and 210P, via the first plug 311 andsecond plug 321. That is to say, the connective wiring 331 is a rewiringlayer (RDL (Re-Distribution Layer)). Details will be described later,but as shown in FIG. 20, there are cases wherein the connective wiring331 has a concave portion 331C in the upper face thereof.

(f) Passivation Film 401

As shown in FIGS. 19 and 20, a passivation film 401 is provided on theback face (upper face) side of the semiconductor substrate 101 which isopposite from the front face (lower face) on which the wiring layer 110is provided, via an insulating film 102. Now, the passivation film 401is provided on the upper face side of the layered body wherein thesensor substrate 100 and logic substrate 200 have been bonded together,so as to cover the connecting conductive layer 301.

The passivation film 401 includes a first passivation film 411 andsecond passivation film 412. The first passivation film 411 and secondpassivation film 412 each are sequentially layered on the back face(upper face) of the semiconductor substrate 101.

As shown in FIG. 20, with in the pad portion PAD, the first passivationfilm is provided so as to cover the inner face of the concave portion331C that is formed on the upper face of the connective wiring 331. Thefirst passivation film 411 is a SiN film, for example, and protectsmetal making up the connective wiring 331 from dispersing outside. Thesecond passivation film 412 is provided in the upper face of theconnective wiring 331 so as to be embedded within the concave portion331C.

(g) Blocking Film 500, Flat Film 501

A blocking film 500 is provided to the upper face of the passivationfilm 401, as shown in FIG. 19. Now, the blocking film 500 is provided onthe back face (upper face) of the semiconductor substrate 101 so as tobe located between the pixels P. That is to say, the blocking film 500has an opening provided in the light receiving face JS of the photodiode21, and is formed such that the flat face shape is in a grid form. Asshown in FIGS. 19 and 20, the flat film 501 is provided so as to coverthe upper face of the passivation film 401 on which the blocking film500 is formed.

Color Filter CF

A color filter CF is provided to the back face (upper face) side of thesemiconductor substrate 101 in the pixel region PA, as shown in FIG. 19.Now, the insulating film 102, passivation film 401, and flat film 501are provided to the back face (upper face) side of the semiconductorsubstrate 101, as shown in FIG. 19, and the color filter CF is formed onthe upper side of the flat film 501 thereof.

The color filter CF is formed so that the incident light H input fromthe back face (upper face) side of the semiconductor substrate 101 viathe on-chip lens OCL is colored in being transmitted. For example, thecolor filter CF is formed so that light of a predetermined wavelengthregion, out of the visible light incident as incident light H, isselectively transmitted.

The color filter CF includes a red filter layer (unshown), green filterlayer (unshown), and blue filter layer (unshown), for example, and eachof the three primary color filter layers thereof are disposed to as tocorrespond to the pixels P in a Bayer array.

(i) On-Chip Lens OCL, Lens Material Film 601

An on-chip lens OCL is provided in the pixel region PA so as tocorrespond to each of the multiple pixels P, as shown in FIG. 19. Theon-chip lens OCL is provided on the upper face of the color filter CF onthe back face (upper face) side of the semiconductor substrate 101.

The on-chip lens OCL is a convex lens that protrudes upward in a convexmanner from the back face (upper face) side of the semiconductorsubstrate 101, and collects the incident light H input from the backface (upper face) side of the semiconductor substrate 101, to thephotodiode 21.

While details will be described later, the on-chip lens OCL if formed byprocessing a lens material layer 601 (see FIG. 20) which is formed onthe upper face of the flat film 501 via the color filter CF. The lensmaterial layer 601 is provided so as to cover the upper face of the flatfilm 501 in the periphery region SA which includes a pad portion 601,without being processed by the on-chip lens OCL, as shown in FIG. 20.

Manufacturing Method

The principal portions regarding a manufacturing method to manufacturethe above-described solid-state imaging device 1 will be described.FIGS. 22 through 31 and diagrams illustrate principal portions regardinga manufacturing method of the solid-state imaging device according to asixth embodiment. FIG. 22 is a manufacturing flow diagram. FIGS. 23through 31 are diagrams illustrating a cross-section of the pad portionPAD, similar to FIG. 20. A cross-section similar to FIG. 19 is omittedin the diagrams, but the portions are formed, similar to FIGS. 23through 31. According to the present embodiment, the steps shown in FIG.22 are performed, as shown in FIGS. 23 through 31. Subsequently, thesolid-state imaging device 1 is manufactured by dicing, using a blade(unshown) in a scribe region LA.

Manufacturing processes in the event of manufacturing the solid-stateimaging device 1 will be described in sequence.

Formation of Sensor Substrate 100

First, the sensor substrate 100 is formed (ST10), as shown in FIG. 22.Now, as shown in FIG. 23, the sensor substrate 100 is formed byproviding parts such as the wiring layer 110, insulating film 120, andthe like on the front face (upper face) of the semiconductor substrate101. In the present step, the parts such as the insulating film 102 orthe like are not formed on the back face (upper face in FIG. 23, lowerface in FIGS. 19 and 20) side of the semiconductor substrate 101 that isincluded in the sensor substrate 100.

In the present step, prior to the process shown in FIG. 23, a photodiode21 is provided to the pixel region PA of the semiconductor substrate 101(see FIG. 19). Also, a semiconductor circuit device (unshown) such as apixel transistor Tr (see FIG. 21) or the like is provided to the frontface (upper face in FIG. 23) side of the semiconductor substrate 101.

The wiring layer 110 is then provided so as to cover the entire frontface (upper face) of the semiconductor substrate 101, as shown in FIG.23. That is to say, a wiring layer 110 is formed on the face of thesemiconductor substrate 101 that faces the logic substrate 200.

Specifically, the wiring layer 110 is provided by alternately forming aninter-layer insulating film which makes up the insulating film 1102 anda wiring 110H which includes the pad wiring 110P (see FIG. 19). Forexample, the wiring 110H (see FIG. 19) such as the pad wiring 110P isformed using metallic material such as aluminum. Also, the insulatingfilm 1102 (see FIG. 19) is formed using a silicon oxide material. Thatis to say, the pad wiring 110P is provided within the wiring layer 110.

Also, an insulating film 120 is provided so as to cover the entire frontface (upper face in FIG. 23, lower face in FIGS. 19 and 20) of thesemiconductor substrate 101. For example, a silicon oxide film isprovided as the insulating film 120. Alternatively, a silicon nitridefilm may be provided as the insulating film 120.

Formation of Logic Substrate 200

Next, the logic substrate 200 is formed (ST20), as shown in FIG. 22.Now, as shown in FIG. 24, the logic substrate 200 is provided bysequentially forming the wiring layer 210 and insulating film 220 on thefront face (upper face) of the semiconductor substrate 201. In thepresent step, prior to the process shown in FIG. 24, a semiconductorcircuit device (unshown) is provided to the front face side of thesemiconductor substrate 201.

The wiring layer 110 is then provided so as to cover the entire frontface (upper face) of the semiconductor substrate 201, as shown in FIG.24. That is to say, a wiring layer 210 is formed on the face of thesemiconductor substrate 201 that faces the sensor substrate 100.

Specifically, the wiring layer 210 is provided by alternately layeringan inter-layer insulating film which makes up the insulating film 210Zand a wiring 210H which includes the pad wiring 210P (see FIG. 19),multiple times. For example, the wiring 210H (see FIG. 19) such as thepad wiring 110P is formed using metallic material such as aluminum. Thatis to say, the pad wiring 210P is provided within the wiring layer 210.Also, the insulating film 210Z (see FIG. 19) is formed using a siliconoxide material.

Also, an insulating film 220 is provided so as to cover the entire frontface (upper face) of the wiring layer 210 thereof. For example, asilicon oxide film is provided as the insulating film 220.Alternatively, a silicon nitride film may be provided as the insulatingfilm 220.

Bonding Together of Sensor Substrate 100 and Logic Substrate 200

Next, as shown in FIG. 22, the sensor substrate 100 and logic substrate200 are bonded together (ST30). Now, as shown in FIG. 25, the wiringlayer 110 of the sensor substrate 100 and the wiring layer 210 of thelogic substrate 200 face each other. By joining together the wiringlayer 110 of the sensor substrate 100 and the wiring layer 210 of thelogic substrate 200, the two are bonded together. For example, thebonding herein is performed with plasma joining.

Thinning of Sensor Substrate 100

Next, as shown in FIG. 22, the sensor substrate 100 is thinned (ST 40).Now, as shown in FIG. 26, for example by performing thinning processingof the face (upper face) of the semiconductor substrate 101, which isincluded in the sensor substrate 100, that is on the opposite side as tothe face (lower face) that faces the logic substrate 200, the sensorsubstrate 100 is thinned. For example, CMP (Chemical MechanicalPolishing) processing is performed as a thinning processing.

Formation of Trench TR, Pad Openings V1 and V2

Next, as shown in FIG. 22, the trench TR and pad openings V1 and V2 areformed (ST 50). Now, as shown in FIG. 27, a trench TR is provided to theinsulating film 102 that covers the upper face of the semiconductorsubstrate 101 which is included in the sensor substrate 100.

As shown in FIG. 27, the pad opening V1 is provided above the pad wiring110P of the sensor substrate 100. Also, the pad opening V2 is providedabove the pad wiring 210P of the logic substrate 200. The pad openingsV1 and V2 are provided so as to pass through from the upper face of thepad wirings 110P and 210P to the upper face of the insulating film 102.That is to say, the pad openings V1 and V2 are formed so as to passthrough the semiconductor substrate 101 which is included in the sensorsubstrate 100.

According to the present embodiment, for the respective pad openings V1and V2, the upper side opening portions V11 and V21 and the lower-sideopening portions V12 and V22 are provided so as to be layered in thedepth direction z. Also, the insulating film 102 is provided so as tocover the inner face of the upper-side opening portions V11 and V21.

Specifically, according to the present process, first, as shown in FIG.27, as a layer that makes up the insulating film 102, a silicon oxidefilm, for example, is provided to the back face (upper face) of thesemiconductor substrate 101 which is included in the sensor substrate100. Also, by processing the silicon oxide film thereof, the trench TRis provided.

Also, by processing the floor face of the trench TR, the upper-sideopening portions V11 and V21, which are included in the pad openings V1and V2, are provided. Now, the upper-side opening portion V11 that isincluded in the pad opening V1 is formed by removing portions that arepositioned above the position wherein the upper face of the pad wiring110P of the sensor substrate 100 is not exposed. That is to say, theupper-side opening portion V11 is provided by opening up until justprior to the pad wiring 110P provided on the sensor substrate 100.Conversely, the upper-side opening portion V21 that is included in thepad opening V2 is formed by removing portions that are positioned abovethe position wherein the upper face of the pad wiring 210P of the logicsubstrate 200 is not exposed. That is to say, the upper-side openingportion V21 is provided by opening up until just prior to the pad wiring210P provided on the logic substrate 200.

Also, as a layer that makes up the insulating film 102, a silicon oxidefilm is provided so as to cover the inner faces of the upper-sideopening portions V11 and V21. Also, the lower-side opening portions V12and V22 are provided by processing the floor portions of the upper-sideopening portions V11 and V21.

Now, the lower-side opening portion V12 is provided so that the upperface of the pad wiring 110P of the sensor substrate 100 is exposed. Thatis to say, the lower-side opening portion V12 is formed so that theupper face of the pad wiring 110P is exposed in the wiring layer 110 ofthe sensor substrate 100, and the upper portion thereof passes through.Also, the lower-side opening portion V22 is provided so that the upperface of the pad wiring 210P of the logic substrate 200 is exposed. Thatis to say, in the layered body of the sensor substrate 100 and logicsubstrate 200, the lower-side opening portion V22 is formed so that theupper side of the pad wiring 210 of the logic substrate 200 is exposedand the upper portion thereof passes through. For example, an etch-backprocessing is performed so as to simultaneously remove the portionsprovided above the pad wirings 110P and 210P, thereby forming each ofthe lower-side opening portions V12 and V22.

For example, the portions are formed so as to follow the conditionsdescribed below.

(For the trench TR)⋅depth DT ⋅ ⋅ ⋅ 100 nm˜1 μm⋅length L ⋅ ⋅ ⋅ 10 μm ormore⋅width W ⋅ ⋅ ⋅ 2 μm or more

(For the pad opening portion V1)⋅depth D1 ⋅ ⋅ ⋅ 3˜7 μm

(Distance from the floor face of the trench TR to the upper face of thepad wiring 110P)⋅width H11 of upper opening portion V11 ⋅ ⋅ ⋅ 1.5˜5.5μm⋅width H12 of lower opening portion V12 ⋅ ⋅ ⋅ 1˜5 μm

(For the pad opening portion V2)⋅depth D2 ⋅ ⋅ ⋅ 5˜15 μm

(Distance from the floor face of the trench TR to the upper face of thepad wiring 210P)⋅width H11 of upper opening portion V21 ⋅ ⋅ ⋅ 1.5˜5.5μm⋅width H12 of lower opening portion V22 ⋅ ⋅ ⋅ 1˜5 μm

Note that in the above description, the pad openings V1 and V2 areformed after the trench TR is formed, but conversely, the trench TR maybe formed after the formation of the pad openings V1 and V2 have beenperformed first.

Connection Between Sensor Substrate 100 and Logic Substrate 200

Next, as shown in FIG. 22, the sensor substrate 100 and logic substrate200 are connected (ST 60). In the event of connecting the sensorsubstrate 100 and logic substrate 200, the processes shown in FIGS. 28through 31 are performed in sequence. Thus, a connecting conductivelayer 301 is provided to the pad portion PAD, and the pad wiring 110P ofthe sensor substrate 100 and the pad wiring 210P of the logic substrate200 are electrically connected.

In the present step, a metal layer 301M is formed, as shown in FIG. 28.Now, the metal layer 301M is formed by embedding a metallic materialinto the trench TR and the pad openings V1 and V2 via a barrier metallayer (unshown), and covering the upper face of the insulation layer102.

While omitted from the diagram, the barrier metal layer (unshown) isprovided so as to cover the side faces of the upper-side openingportions V11 and V21 via the insulating film 102, and to cover the sidefaces and floor faces of the lower-side opening portions V12 and V22.Also, a barrier metal layer (unshown) is provided so as to cover theside face and floor face of the trench TR. For example, the barriermetal layer (unshown) is formed under the following conditions.

Conditions for Forming Barrier Metal Layer

Material: Ta, or layered body of Ta and TaN

Thickness: Approximately 10 to 200 nm

Film Forming Method: Sputtering

Also, the metal layer 301M is provided so as to be embedded within theupper-side opening portions V11 and V21 and the lower-side openingportions V12 and V22, via the barrier metal layer (unshown). Also, themetal layer 301M is provided so as to cover the side face and floor faceof the trench TR, via the barrier metal layer (unshown). For example,the metal layer 301M is formed under the following conditions.

Conditions for Forming Metal Layer 301M

Material: Cu

Thickness DT0 from trench TR floor face: 1 to 5 μm

Film Forming Method: Electroplating

The electroplating herein is performed with a two-step depositionmethod, for example. Specifically, in the first step, current is set to0.1 to 5 A (amperes), and a Cu film is formed at a thickness ofapproximately 50 to 200 nm. Next, in the second step, current is set to1 to 8 A, for example, and a Cu film is formed at a thickness ofapproximately 800 nm to 5 μm. At this time, the number of waferrotations and additives are adjusted as appropriate.

That is to say, the metal layer 301M is formed with copper plating so asto cover the portions forming the first plug 311, second plug 321, andconnective wiring 331 (see FIG. 20).

At this time, as shown in FIG. 28, the metal layer 301M is formed so asto include a pit PIT which is a minute space. For example, multiplespaces having the size of 1 to 20 nm are formed as pits PIT.

The pit PIT is formed within the metal layer 301M when oxygen (O₂)bubbles occur on the anode side of a plated device, and attach to andare fixed to the plated surface. Particularly, in the case that theanode is positioned lower than the wafer forming the metal layer 301M,bubbles that occur with the anode electrode move upward, and accordinglythere are cases wherein a large number of pits PIT may be encapsulated.Additionally, from bubbles occurring when the plating liquid is stirredin a plating tank, or when a wafer is placed in the plating liquid,there are cases that the pit PIT forms on the inner portion of the metallayer 301M.

Subsequently, by performing heat processing, crystal growth on the Cuthat makes up the metal layer 301M is enabled, and reliability of thewiring is improved. For example, heat processing is performed on themetal layer 301M under the following conditions.

Heat Processing Conditions

heat processing temperature: 100° C. to 400° C.

heat processing time: 30 seconds to 3 minutes (in the case of a hotplate) or 15 minutes to 2 hours (in the case of annealing furnace)

From the heat processing herein, as shown in FIG. 29, pits PIT (see FIG.28) are collected on the metal layer 301M, and a void MV which is aspace greater than the pits PIT is formed. For example, a space that is140 to 500 nm vertically and 100 to 250 nm horizontally is formed as avoid MV.

As shown in FIG. 30, by removing the upper face of the metal layer 301M,the connecting conductive layer 301 is formed. Now, thinning processingof the metal layer 301M, such as CMP processing, is performed, and theupper face of the insulating film 102 is processed so as to be exposed,whereby the connecting conductive layer 301 is formed.

Thus, as shown in FIG. 30, the connecting conductive layer 301 is formedso as to include the first plug 311, second plug 321, and connectivewiring 331. In the connecting conductive layer 301, the inner portion ofthe void MV is exposed on the upper face of the connective wiring 331,and a concave portion 331C is formed on the upper face thereof. Forexample, a concave portion 331C that is 70 to 200 nm vertically and 100to 250 nm horizontally is provided to the upper face of the connectivewiring 331.

Formation of Passivation Film 401

Next, as shown in FIG. 22, a passivation film 401 is formed (ST 70).Now, as shown in FIG. 31, the passivation film 401 is formed on theupper face of the insulating film 102 so as to cover the upper face ofthe connective wiring 331. In the present step, first, a firstpassivation film 411 that is included in the passivation film 401 isformed.

The first passivation film 411 is formed so as to cover the inner faceof the concave portion 331C provided on the upper face of the connectivewiring 331 and the upper face of the insulating film 102. For example,the first passivation film 411 is formed under the following conditions.

Formation Conditions of First Passivation Film 411

Material: SiN

Film Thickness: 50 to 100 nm

Film Forming Method: Parallel plate type plasma CVD (Chemical VaporDeposition) method

Condition Details

-   -   Gas flow rate: SiH₄:NH₃:N₂=1:1:20    -   High frequency power: 300 to 1,000 W    -   Pressure: 0.5 to 7.0 Torr    -   Temperature: 250 to 400° C.    -   Time: 30 seconds to 1 minute    -   Film Thickness: 50 to 100 nm

Next, the second passivation film 412 is formed. The second passivationfilm 412 is provided to as to be embedded in the inner portion of theconcave portion 331C on the upper face of the connective wiring 331. Forexample, a second passivation film 412 made of SiO₂ is formed under thefollowing conditions.

Formation Conditions of First Passivation Film 411

Film Forming Method: High density plasma (HDP) CVD method

Film Thickness: 100 to 150 nm

Condition Details

-   -   Gas flow rate: SiH₄:O₂=1:1.5    -   Source bias: 5,000 to 8,000 W    -   Substrate Bias: 5,000 to 8,000 W    -   Pressure: 7 to 11 Torr    -   Temperature: 300 to 350° C.    -   Time: 1 minute

Note that the “high density plasma CVD method” is a method to form afilm by depositing films by chemical vapor deposition using the gas madeinto high density plasma, and indicates converting gas into high densityplasma that is of a plasma density of 1017 m-3 or greater.

Formation of Flat Film 501 and the Like

Next, as shown in FIG. 22, the flat film 501, color filter CF, andon-chip lens OCL are formed in sequence (ST 80). Now, as shown in FIG.19, a blocking film 500 is provided to the upper face of the passivationfilm 401. For example, the blocking film 500 is formed with a blockingmaterial under the following film-forming conditions. Subsequently, theblocking material film is formed by patterning under the followingetching processing conditions.

Film Forming Conditions

Materials: metallic material such as W (tungsten), Cu (copper), Al(aluminum) (may be layered with Ti)

Film Thickness: approximately 50 to 500 nm

Film forming Method: Sputtering or the like

Etching Processing Conditions

-   -   Etching Gas: SF6:C12=1:2    -   Pressure: 5 to 20 m Torr    -   Source Bias: 100 to 1,000 W    -   Substrate Bias: 10 to 200 W    -   Temperature: room temperature    -   Time: 30 to 120 seconds

Note that for the etching gas, besides the above described, an etchinggas such as nitrates, acetic acids, hydrochloric acids, sulfuric acids,or the like. Also, besides a dry etching processing, a wet etchingprocessing may be performed.

As shown in FIGS. 19 and 20, the flat film 501 is formed on the upperface of the passivation film 401. As shown in FIG. 19, a color filter CFis formed on the upper face of the flat film 501 in the pixel region PA.The color filter CF is formed by forming a coated film by coating with acoating liquid that includes a color pigment and photo resist resin,with a coating method such as spin coating. Subsequently, the coatedfilm thereof is formed by patterning with a lithograph technique. Thus,each of three primary color filter layers are sequentially formed,thereby providing a color filter CF.

As shown in FIG. 19, the on-chip lens OCL is formed on the upper face ofthe color filter in the pixel region PA. The on-chip lens OCL is formedby processing a lens material layer 601 that is formed on the upper faceof the flag film 501 via a color filter CF (see FIG. 20).

For example, the lens material layer 601 is provided by forming anorganic resin material film on the upper face of the flat film 501. Uponproviding the photoresist film (unshown) on the lens material layer 601,the photoresist film (unshown) is patterned in a lens shape. The lensmaterial layer 601 is this subjected to etch-back processing, using thelens shape resist pattern (unshown) as a mask. Thus, the on-chip lensOCL is formed. Note that besides that described above, an on-chip OCLmay be formed by subjecting the lens material layer 104 to reflowprocessing after the patterning process.

As shown in FIG. 20, the lens material layer 601 is provided so as tocover the upper face of the flat film 501 in the periphery region SAwhich includes the pad portion 601, without being processed into anon-chip lens OCL. Thus, following each step, the solid-state imagingdevice is completed.

Conclusion

As described above, according to the present embodiment, the sensorsubstrate 100 on which a pad wiring 110P is provided is formed. Next, alogic substrate 200 on which a pad wiring 210P is provided is formed.Next, the sensor substrate 100 is caused to face the upper face of thelogic substrate 200, so as to be layered, and bonded together. Next, onthe layered bode of the sensor substrate 100 and logic substrate 200, apad opening V1 is formed on the upper face of the pad wiring 110P, whilea pad opening V2 is formed on the upper face of the pad wiring 210P.Next, a metallic material is embedded in the inner portion of the padopening V1 and pad opening V2, and the first plug 311 and second plug321 are provided, while a connective wiring 331 that connects the firstplug 311 and second plug 321 is provided, thereby forming a connectingconductive layer 301. Next, a passivation film 401 is formed on theconnecting conductive layer 301 so as to cover the upper face of theconnective wiring 331.

In the case herein, there are cases wherein a concave portion 331C isprovided on the upper face of the connective wiring 331 provided to thepad portion PAD (see FIG. 30). Therefore, there are cases wherein areactant such as a processed gas or chemical solution, used in theprocesses performed after the connective wiring 331 has been formed, andthe connecting conductive layer 301 react, and a portion of the concaveportion 331C is eliminated, or cases wherein generation of abnormalcrystals occurs. Consequently, there are cases wherein product yield anddevice reliability deteriorate.

In order to prevent the occurrence of such defects, a passivation film401 covers the upper face of the connecting conductive layer 301.However, unlike the case of the present embodiment, for example in thecase that the second passivation film 412 of a SiO₂ film is formed underthe conditions of a comparison example described below, there are caseswherein sufficiently preventing the above-described defects isdifficult.

Formation Conditions of Second Passivation Film 412 (Comparison Example)

Film Forming Method: parallel plate type plasma CVD method

Detailed Conditions

Film Thickness: 100 to 150 nm

Detailed Conditions

-   -   Gas flow rate: SiH₄:N₂O=1:20    -   High frequency power: 100 to 700 W    -   Pressure: 0.5 to 5 Torr    -   Temperature 300 to 400° C.    -   Time: 1 minute

In the case of the parallel plate type plasma CVD method, steppedcoverage is poor, and the coverage rate is insufficient, which isascribed to difficulties in appropriately filling in the inner portionof the concave portion 331C having a high aspect ratio. Therefore, thereare cases wherein a space (slit) is provided to a portion correspondingto the concave portion 331C in the second passivation film 412.

Also, in the case of the above-described comparison example, whenperforming “cleaning processing” under the following conditions, thesecond passivation film 412 is removed in the space (slit) portionthereof, in which case the width of the space thereof is widened.Specifically, in the cleaning processing, it has been confirmed that oneside is widened by approximately 1 to 10 nm. For example, the cleaningprocessing is performed after the second passivation film 412 is formedand prior to the formation of the blocking film 500, and the width ofthe spacing thereof is widened. Additionally, there are cases whereinthe cleaning processing performed after the formation of the secondpassivation film 412 and before another rewiring is formed on the secondpassivation film 412, and the width of the spacing thereof is widened.

Cleaning Processing Conditions

Cleaning Solution: water:HF=100:1

Processing Temperature: 10 to 30° C.

Cleaning Time: 30 seconds to 2 minutes

Accordingly, in the case that a pinhole exists in a portion provided aconcave portion 331C in the first passivation film 411 made of SiN, aconnecting conductive layer 301 positioned directly underneath thereofis exposed.

Additionally, for example, when performing “dry etching processing”under the following conditions, there are cases wherein the SiO₂ film isremoved with the space (slide provided to the passivation film 401, andthe width of the space thereof widens. For example, there are caseswherein the “dry etching processing” is performed after the formation ofthe second passivation film 412 and before another rewiring is formed onthe second passivation film 412, and the width of the spacing thereof iswidened.

Dry Etching Processing Conditions

Etching Gas: hydrogen fluoride (HF) type of gas

Temperature: room temperature

Pressure: 10 to 70 m Torr

Source Power: 700 to 2,000 W

Gas Flow Rate: CF4/CHF3/Ar=3/1/10

Substrate Bias: 300 to 1,000 W,

Time: approximately 30 seconds to 2 minutes

Therefore, for example, when the blocking material film is patternedwith the “dry etching processing” in the above-described blocking film500 forming process (ST 80), there are cases wherein this reacts withthe Cu in the concave portion 331 C portion of the connecting conductivelayer 301. Accordingly, there are cases wherein a portion of the concaveportion 331C of the connecting conductive layer 301 is removed and lost,and cases wherein the generation of abnormal crystals occur.

FIGS. 32 and 33 are diagrams illustrating a state of a comparisonexample according to the sixth embodiment. Now, FIG. 32 shows anelectronic microscope photograph of a cross-section. FIGS. 33A through33C show a situation in which a portion of the concave portion 331C ofthe connective wiring 331 has been lost, and a generated item hasoccurred from abnormal reaction with the connective wiring 331. FIG. 33Ais an optical microscope photograph indicating the upper face of acomparison example. In FIG. 33A, multiple connective wirings 331 whichextend in the horizontal direction are disposed in the verticaldirection. FIG. 33B is an optical microscope photograph indicating across-section of a portion wherein a portion of the concave portion 331Cof the connective wiring 331 has been lost. FIG. 33C is an opticalmicroscope photograph indicating a generated item that occurred from anabnormal reaction with the connective wiring 331.

As shown in FIG. 32, in the case of the comparison example, when theupper face of the connective wiring 331 on which the concave portion331C is provided is covered with the passivation film 401, there arecases wherein a space S (slit) is formed in a portion corresponding tothe concave portion 331C in the passivation film 401. Thus, there arecases wherein sufficiently filling in the concave portion 331C with thepassivation film 401 is difficult.

As shown with circles in FIG. 33A, upon performing the processes, thereare cases wherein the portion of the concave portion 331C of theconnective wiring 331 is lost. Specifically, as shown in FIG. 33B, thereare cases wherein below the passivation film 401 becomes hollow. Also,as shown in FIG. 33C, there are cases wherein a generated time E isformed on the connective wiring 331 by an abnormal reaction with theconnective wiring 331.

Thus, in the comparison example, loss of the portion on which theconcave portion 331C is provided and generation of abnormal crystals canoccur, and accordingly product yield and device reliability candeteriorate. Particularly, as described above, in the case of providinga connecting conductive layer 301 by forming the metal layer 301M so asto fill in the inner portion of the pad openings V1 and V2 that passthrough the semiconductor substrate 101, there are cases whereinoccurrences of defects herein are elicited.

In the case of forming the first plus 311 and second plug 321 which areTSVs, by filling Cu into the deep pad openings V1 and V2, platingconditions by Cu or the like by electrolysis is limited. Therefore, agreater number of bubbles of the O₂ generated from the anode side of theplating device attaché to the portion of the metal layer 301M that isclosest to the connective wiring 331 (RDL) portion, and the metal layer301M is formed so as to include the pits. Additionally, the metal layer301M which is a plating layer is formed so as to include pits, frombubbles occurring when the plating liquid is stirred in a plating tank,or when a wafer is placed in the plating liquid. By performing heatprocessing subsequently, a minute pit can grow into an enormous void.The portion of the connective wiring 331 (RDL) has a large area,whereupon many pits can collect and a large void is readily formed.Accordingly, with Cu polishing, a large flaw to the concave portion 331Con the upper face of the connective wiring 331 (RDL) that links multipleTSVs can readily occur.

Also, in the case of the comparison example, in order to fill in theinner portion of the concave portion 331C, the passivation film 401 hasto be made thicker (e.g., a thickness of 300 to 500 nm). Therefore, thedistance between the on-chip lens OCL and photodiode 21 becomes longer,and properties such as pixel sensitivity can deteriorate. Accordingly,there are cases wherein image quality of an imaged image deteriorates.Also, even in the case of forming a thicker film, depending on theevenness or layout of the film forming process, filling in may not beperformed sufficiently, and accordingly a space S can occur as shown inFIG. 32.

FIG. 34 is a perspective view showing the connective wiring 331 of theconnecting conductive layer 301. As shown in FIG. 34, in the case thatthe thickness DT of the connective wiring 331 and the width W or lengthL have the relation shown in Expressions (1) or (2) below, theabove-described defects can occur.W≥10×DT  (1)L≥10×DT  (2)

That is to say, in the case that the width W or length L of theconnective wiring 331 is 10 times or greater than the thickness DT, theabove-described defects can occur. We can see from actual results that,in the case that the width W or length L of the connective wiring 331 is10 times or greater than the thickness DT, the pits existing on a largearea can be concentrated in specific areas, and become an enormous void,and accordingly the above-described defects can occur. Note that in theforming process of the connective wiring 331, the maximum thickness isDT0, as shown in FIG. 28, but the maximum thickness DT0 and theoccurrence of a concave portion 331C do not have to be considered inparticular.

In the case of the present embodiment as opposed to the above-describedcomparison example, the second passivation film 412 is formed by forminga SiO₂ film with a “HDP CVD method”, as described above, whereby thepassivation film 401 is provided. In the case of the HDP CVD method, aplasma active ion is used, and film forming is progressed while shavingthe film that has overhung and deposited on the upper portion of thegroove, whereby coverage is sufficient high. Accordingly, even if thefilm thickness is not thick, appropriately filling in the inner portionof the concave portion 331C can be readily performed.

FIG. 35 is a diagram illustrating a portion of the connective wiring 331whereupon a concave portion 331C has been provided, according to thesixth embodiment. As shown in FIG. 35, according to the case of thepresent embodiment, when the upper face of the connective wiring 331 onwhich the concave portion 331C is provided is covered with a passivationfilm 401, a space S is not formed in the portion of the passivation film410 corresponding to the concave portion 331C. Thus, according to thepresent embodiment, the inner portion of the concave portion 331C can besufficiently filled in with the passivation film 401.

Therefore, according to the present embodiment, unlike the case of thecomparison example described above, loss of the concave portion 331C onthe connective wiring 331 and generation of abnormal crystals can beprevented with a thin film passivation film 401. That is to say,according to the present embodiment, in the case of patterning theblocking material film with “dry etching processing” in the formingprocess (ST 80) of the blocking film 500 and so forth, the passivationfilm 401 can effectively protect the connective wiring 331. Therefore,according to the present embodiment, product yield and devicereliability can be improved. Also, image quality of an imaged image canbe improved.

Modifications

A case of forming the passivation film 401 by forming a SiO₂ film withan HDP CVD method is described above, but this should not be limited.Besides a SiO₂ film, a SiOC film or SiOF film may be formed. Also, apassivation film 401 may be formed with another CVD method having highcapability for filling in.

Modification 1-1

For example, as in the conditions below, the second passivation film 412may be formed by forming an SiO₂ film with an “O3 TEOS (Tetra ethylortho silicate) CVD method. Besides the SiO₂ film, the secondpassivation film 412 may be formed with a SiOC film or SiOF film.

Formation Condition of Second Passivation Film 412

Film Forming Method: O3 TEOS CVD method

Film Thickness: 100 to 150 nm

Detail Conditions

-   -   Gas Flow Rate: TEOS/OE/He=1:30:10    -   High Frequency Power: none    -   Pressure: 30 to 100 Torr    -   Temperature: 300 to 400° C.    -   Time: DR=10 to 50 nm/min

The above-described “O3 TEOS CVD method” is a method to form a film witha CVD method, using O3 and TEOS.

This film forming method has sufficiently high coverage for the reasonthat fluidity is high because of high-density ozone, whereby even if thefilm thickness is not thick, the inner portion of the concave portion331C can be readily filled in.

Modification 1-2

For example, the second passivation film 412 of an SiO₂ film may beformed with an “ALD (Atomic Layer Deposition)”, as described in theconditions below. Besides a SiO₂ film, the second passivation film 412may be formed with a SiOC film or SiOF film.

Forming Conditions of Second Passivation Film 412

Film Forming Method: ALD method

Film Thickness: 30 to 50 nm

The above-described “ALD method” is a film forming method that depositsan atomic layer.

The film forming method herein can have an even film thickness controlat an atomic level, and coverage is sufficiently high, whereby even ifthe film thickness is not thick, the inner portion of the concaveportion 331C can be appropriately filled in readily.

Seventh Embodiment

Manufacturing Method, etc.

According to the present embodiment, the forming conditions of thesecond passivation film 412 differ from that of the sixth embodiment.Other than this point, and points relating thereto, the presentembodiment is similar to the sixth embodiment. Therefore, duplicateportions will be omitted from description.

According to the present embodiment, the second passivation film 412 isformed under the following conditions. That is to say, for example, thesecond passivation film 412 is formed by forming an organic SOG (Spin onglass) film with a “coating method” such as spin coating.

Forming Conditions of Second Passivation Film 412

Film Forming Method: Spin Coating

Film Thickness: 50 to 100 nm

Detail Conditions

-   -   Material: HSQ (Hydrogen Silsesquioxane)    -   Coating Rotation: 1500 to 2500 rpm    -   Baking Conditions: 80 to 150° C., 60 to 180 seconds    -   Heat Processing Conditions for Bridging: 300 to 400° C., 1 to 10        minutes

Specifically, upon spin-coating with the coating fluid that includes HSQat the above-described coating rotation, baking processing is performedunder the baking conditions described above. Thereafter, heat processingis performed under the heat processing conditions described above forbridging. Thus, an inorganic SOG film having a refractive index ofapproximately 1 to 1.4 is formed.

The above-described “coating method” is a film forming method to form acoated film by coating a face with a coating fluid that includes acoating film material. The film forming method herein has sufficientcoverage, since the coating fluid flows into the narrow spaces betweenthe wiring whereby a coating film is formed. Accordingly, filling in theinner portion of the concave portion 331C appropriately can be morereadily performed than in the case of a parallel plate type CVD method.

Also, the film forming method herein can be made this, since theflatness thereof is high. Accordingly, coverage is higher than with adeposition method such as the HDP CVD method described according to thesixth embodiment, and therefore is more favorable.

Conclusion

As described above, according to the present embodiment, a passivationfilm 401 is formed by forming an insulating film with a “coatingmethod”. Therefore, as described above, the inner portion of the concaveportion 331C can be appropriately filled in. Accordingly, according tothe present embodiment, product yield and device reliability can beimproved. Also, the image quality of imaging images can be improved.

Note that according to the above-described embodiment, description isgiven in the case of providing a second passivation film 412 by formingan inorganic SOG film with an inorganic material such as HSQ, but is notlimited to this. The second passivation film 412 may be formed byforming an organic SOG film with an organic material. For example, MSQ(Methyl silsesquioxane), Par (polyarylene), PAE (polyarylene ether), BCB(Benzocyclobutene) or the like may be used to form the film.

For example, the above-described materials are used to form the secondpassivation film 412 under the following conditions.

Film Forming Method: Spin coating method

Film Thickness: 50 to 100 nm

Detail Conditions

-   -   Coating Rotations: 1500 to 2500 rpm    -   Baking Conditions: 300 to 350° C., 30 to 90 seconds    -   Heat Processing Conditions for Bridging: 300 to 350° C., 5 to 60        seconds

Eighth Embodiment

Device Configuration and so Forth

FIG. 36 is a diagram illustrating the principal portion configuration ofa solid-state imaging device according to an eighth embodiment.

Now, similar to FIG. 20, FIG. 36 illustrates a cross-section taken alongline XX-XX in FIG. 18.

As shown in FIG. 36, the configuration of the passivation film 401according to the present embodiment differs from the case in the sixthembodiment. Other than this point, and points relating thereto, thepresent embodiment is similar to the sixth embodiment. Therefore,duplicate portions will be omitted from description.

The passivation film 401 is formed in a single layer, as shown in FIG.36, not as a layered body wherein multiple layers are layered together.The passivation film 401 herein is formed so as to fill in the innerfaces of the concave portion 331C provided on the upper face of theconnective wiring 331 and to cover the upper face of the insulating film102. For example, the passivation film 401 is formed under the followingconditions.

Film Forming Conditions of Passivation Film 401

Material: SiN

Film Forming Method: ALD method

Film Thickness: 30 to 50 nm

Detailed Conditions

-   -   Gas Flow Rate: DCS (dichlorosilane):NH₃=1:2    -   High Frequency Power: 30 to 700 W    -   Pressure: 90 to 600 Pa    -   Temperature: 300 to 350° C.    -   Time: 10 seconds to 2 minutes        The above-described film forming method enables control of an        even thickness at the atomic layer level, whereby a film having        high film quality and high coverage of the stepped form can be        formed. Accordingly, coverage is sufficiently high, whereby even        if the film is not thick as in the case of the parallel plate        type CVD method, the inner portion of the concave portion 331C        can be readily filled in.        Conclusion

As described above, in the passivation film 401 forming processesaccording to the present embodiment, a SiN insulating film is formedwith an “ALD method”, whereby the passivation film 401 is formed.Therefore, as described above, the inner portion of the concave portion331C can be appropriately filled in. Accordingly, according to thepresent embodiment, product yield and device reliability can beimproved. Also, the image quality of imaging images can be improved.

Note that according to the above-described embodiment, description isgiven in the case of forming a SiN film with the ALD method as thepassivation film 401, but is not limited to this. The passivation film401 may be formed by forming a SiON film, SiC film, or SiCN film withthe ALD method. Also, the passivation film 401 may be formed by forminga SiN film, SiON film, SiC film, or SiCN film with the HDP CVD method.Additionally, the passivation film 401 may be formed by layering theseas appropriate.

Others

The present embodiment is not to be limited to the descriptions givenabove, and types of modifications can be employed.

In the above-described embodiment, description is given in the case ofproviding a pad opening by forming an upper-side opening portion and alower opening portion of which the width is narrower than the upper-sideopening portion, so as to be layered in the depth direction z, but isnot limited to this. The pad opening may be provided by forming three ormore opening portions having different widths, so as to be layered inthe depth direction z. Also, other than the case of having a stepbetween the upper side opening portion and lower opening portion, thepad opening may be provided so as to have no step. That is to say, thepad opening may be provided having the same width from upper portion tolower portion.

In the above-described embodiment, description is given in the case ofbonding together the sensor substrate 100 and logic substrate 200 withplasma joining, but is not limited to this. For example, an adhesive maybe used to bond the two together.

In the above-described embodiment, description is given in the case ofmanufacturing the sensor substrate 100 which is a rear-projection typeCMOS from a silicon substrate, but is not limited to this. The sensorsubstrate 100 may be manufactured from a so-called SOI (Silicon onInsulator) substrate.

In the above-described embodiment, description is given in the case ofproviding four types as a pixel transistor, which are a transfertransistor, amplifying transistor, selecting transistor, and resettransistor, but is not limited to this. For example, in the case ofproviding three types as a pixel transistor, which are a transfertransistor, amplifying transistor, and reset transistor, the presenttechnology may be applied.

In the above-described embodiment, description is given in the case ofproviding one each of a transfer transistor, amplifying transistor,selecting transistor, and reset transistor for one photodiode, but isnot limited to this. For example, in the case of providing one each ofan amplifying transistor, selecting transistor, and reset transistor formultiple photodiodes, the present technology may be applied.

In the above-described embodiment, description is given in the case ofapplying the present technology to a camera is described, but is notlimited to this. The present technology may also be applied to otherelectronic devices having a solid-state imaging device, such as ascanner or copier.

In the above-described embodiment, description is given in the case thatthe sensor substrate 100 is a “rear projection type” of CMOS imagesensor, but is not limited to this. Also, besides the CMOS image sensor,the present technology may be applied in the case of a CCD type imagesensor.

In the above-described embodiment, description is given in the case ofbonding together the sensor substrate 100 and logic substrate 200, butis not limited to this. The present technology may also be used in thecase of bonding together semiconductor chips other than the sensorsubstrate 100 and logic substrate 200.

In the above-described embodiment, description is given in the case ofproviding one each of a transfer transistor, the case of simultaneouslyremoving the upper and lower portions of multiple pad wirings withetching processing to simultaneously form multiple pad openings havingdifferent depths. However, this is not limited. Additionally, multiplepad openings having different breadths (width, diameter) may be formedsimultaneously with etching processing.

In the above-described embodiment, description is given in the case offorming a connecting conductive layer 301 by forming copper (Cu) into afilm using an electroplating method, but is not limited to this. Besideselectroplating, the present technology may be applied to a case offorming a film with a non-electroplating method. In the case of anon-electroplating method also, bubbles can occur when the platingliquid is stirred, or when a wafer is placed in the plating tank, andaccordingly defects such as those described above can occur. Also,besides copper (Cu), the present technology may be applied in the caseof forming a connecting conductive layer 301 by forming a film with gold(Au), silver (Ag), nickel (Ni), indium (In), tungsten (W), or an alloyof these.

Also, in the above-described embodiment, description is given in thecase that a large void is generated from minute pits with the heatprocessing, and subsequently the inner portion of the void is exposed byfilm-thinning processing and a concave portion is provided on the upperface of the connective wiring, but is not limited to this. The presenttechnology may be applied in the case of providing a concave portion onthe upper face of the connective wiring with another method.

Additionally, the above-described embodiments may be combined asappropriate.

FIG. 37 is a cross-sectional diagram showing a configuration example ofa layered type imaging device 11. FIG. 37 shows a cross-section of thevicinity of three adjacent pixels 21A through 21C, of multiple pixels 21disposed in an array form. As shown in FIG. 37, the layered type imagingdevice 11 is configured by a sensor chip 31 and signal processing chip32 being adhered together with an adhesive layer 33.

The sensor chip 31 is made up of an OCL (On Chip Lens) layer 41,semiconductor substrate 42, and wiring layer 43, in sequence from theupper side in FIG. 37. Note that a solid-state imaging device 21 is aso-called rear-projection type CMOS image sensor, whereby incident lightis input as to the back face (the face facing the upper side in FIG. 37)which faces the opposite side from the front face of the semiconductorsubstrate 42, on which a wiring layer 43 is provided as to thesemiconductor substrate 42 of the sensor chip 31.

In the OCL layer 41, multiple small lenses 44 are disposed for eachpixel 21, and FIG. 37 shows three lenses 44A through 44C that aredisposed corresponding to the pixels 21A through 21C.

In the semiconductor substrate 42, for example, on the inner portion ofa P-type silicon layer (P-well) 45, multiple PDs 46 which arephotoelectric converters are disposed for each pixel 21, and FIG. 37shows three PDs 46A through 46C that are disposed corresponding to thepixels 21A through 21C. The semiconductor substrate 42 is a lightreceiving layer that receives the incident light which is incident intothe layered-type imaging device 11, the PDs 46A through 46C receive theincident light collected by the lenses 44A through 44C and performphotoelectric conversion, and accumulate the load generated therein.

The wiring layer 43 is made up by a wiring 47, which performs loadreadouts of the PD 46 formed in the semiconductor substrate 42, embeddedin an inter-layer insulating film 48, and in the example in FIG. 37, alayer wherein the wiring 47-1 is disposed and a layer wherein the wiring47-2 is disposed form a two-layer configuration.

The signal processing chip 32 is made up of a wiring layer 51 andsemiconductor substrate 52 having been layered together in sequence fromthe upper side of FIG. 37. A logic circuit for driving the sensor chip31 (e.g., see FIG. 1) and a memory and so forth are formed in the signalprocessing chip 32.

The wiring layer 51 is configured such that multiple wirings 53 areembedded in the inter-layer insulating film 54, and in the example inFIG. 37, a layer wherein the wiring 53-1 is disposed, a layer whereinthe wiring 53-2 is disposed, and the wiring 53-3 form a three-layerconfiguration. The wiring 53 performs sending/receiving of signalsbetween the sensor chip 31 and signal processing chip 32, andsending/receiving of signals between the logic circuit on the signalprocessing chip 32.

The semiconductor substrate 52 has a circuit layer wherein multipletransistors 55 are formed, which makes up a logic circuit of the signalprocessing chip 32, and in the example in FIG. 37, only one transistor55 is shown and the other transistors 55 are omitted from the diagram.

As shown in FIG. 37, a gate electrode 56 of the transistor 55 is formedso as to be layered on the semiconductor substrate 52, i.e., so as toprotrude to the wiring layer 51 side, and the gate electrode 56 andwiring 53-3 are connected with a contact unit 57.

In the layered-type imaging device 11, a blocking film 58 is disposedbetween the semiconductor substrate 42 on which the PDs 46 are formedand the semiconductor substrate 52 on this the transistors 55 areformed. For example, the blocking film 58 is disposed in the wiringlayer 51, in a region wherein the wiring 53 is not formed, but using thesame material as the wiring 53 and at the same depth in the layer as thewiring 53 is formed (i.e. so as to form the same plane as the wiring53).

In the example in FIG. 37, a two-layer construction is shown, whereinthe blocking films 58 a-1 and 58 b-1 that are disposed in the same layeras the wiring 53-1 and a blocking film 58-2 that is disposed in the samelayer as the wiring 53-2. For example, aluminum (thickness: 600 nm) isused for the material for the wiring 53 and blocking film 58, and as abarrier metal, TiN (30 nm)/Ti (60 nm) is used.

That is to say, in the process to form the wiring 53, the blocking film58 can be formed at the same time as the wiring 53, and new processes toform the blocking film 58 do not have to be added. That is to say, theblocking film 58 does not add a new blocking layer, but is providedusing the wiring 53. Also, the wiring 53 is connected to the PDs 46 ofthe sensor chip 31 and the logic circuit of the signal processing chip32, but the blocking film 58 is formed so as to be independent therefrom(as a separate dummy pattern from the pattern of the wiring 53).

By providing such a blocking film 58, the layered-type imaging device 11can block the light emitted by a hot carrier of the transistor 55 (whitearrow in FIG. 37) with the blocking film 58, and can suppress theemitted light from negatively influencing the PDs 46.

Now, the light emitting from the hot carrier of the transistor 55causing adverse effects on the PDs 46 will be described with referenceto FIG. 38. FIG. 38 shows a layered-type imaging device 11′ of aconfiguration example according to the related art in which a blockingfilm 58 is not formed. In such a configuration, light emitted by a hotcarrier of the transistor 55 may have been received by a PD 46C, forexample, as shown in the white arrow in FIG. 38. Thus, in the pixelsignal output from the PD 46C, the light amount receiving the lightemitted by a hot carrier of the transistor 55 is added to the lightamount of the incident light collected by the lens 44C, and accordinglythe emitted light can cause adverse effects by appearing in an image asnoise.

Conversely, as shown in FIG. 37, in the layered-type imaging device 11,the blocking film 38 can block the light emitted by a hot carrier of thetransistor 55 from being transported, and the adverse effects from theemitted light thereof can be suppressed, whereby image qualitydeterioration can be prevented.

Note that the blocking film 58 only have to be disposed between thesemiconductor substrate 42 on which the PDs 46 are formed and thesemiconductor substrate 52 on which the transistors 55 are formed aredisposed, and may also be formed only on the wiring layer 43 instead ofthe wiring layer 51, or may be formed on both the wiring layers 51 and43.

Now, the wiring 53 formed in the wiring layer 51 is generally in alayout following strict design rules stipulated by processing conditionssuch as lithography, dry etching, or CMP (Chemical MechanicalPolishing). Therefore, in the case of using the wiring layer 51 to forma blocking film 58, the blocking film 58 is not laid out with just lightblocking as an objective, but the blocking film 58 has to be laid out sothat light can be effectively blocked while following the layout rules.For example, an example of a design rule for the wiring width of thewiring 53 and minimum wiring spacing (the spacing between wirings 53having the smallest possible wiring width thereof) is shown in FIG. 39.

As shown in FIG. 39, the design rules of the wiring 53 is set such that,in the case that the wiring width of the wiring 53 is 1.6 μm or less,the minimum wiring spacing of the wirings 53 is set to 0.4 μm. Also, inthe case that the wiring width of the wiring 53 is greater than 1.6 μmand is 4.6 μm or less, the minimum wiring spacing of the wirings 53 isset to 0.5 μm; in the case that the wiring width of the wiring 53 isgreater than 4.6 μm and is 6.0 μm or less, the minimum wiring spacing ofthe wirings 53 is set to 0.8 μm. Also, in the case that the wiring widthof the wiring 53 is greater than 6.0 μm and is 10.0 μm or less, theminimum wiring spacing of the wirings 53 is set to 1.5 μm; in the casethat the wiring width of the wiring 53 is greater than 10.0 μm, theminimum wiring spacing of the wirings 53 is set to 3.0 μm.

In the case of using a layer of wiring 53 to lay out square blockingfilms 58 according to such design rules, the relation between the widthof the blocking film 38 and the minimum spacing of the blocking films 58(the spacing between blocking films 58 having the smallest possiblewidth thereof) is shown in FIG. 40. In FIG. 40, the horizontal axisshows the width of the blocking film 58 (Island Width) and the verticalaxis shows the minimum space (Min Space) of the blocking films 58.

As shown in FIG. 40, the relation between the width and the minimumspacing of the blocking films 58 is such that, according to the designrules shown in FIG. 39, corresponding to the increase in the width ofthe blocking film 58, the minimum width of the blocking films 58gradually increases. Now, if the ratio of the area blocked by theblocking films 58 as to the entire area in which the blocking films 58are disposed is a duty ratio, the duty ratio is at maximum at the pointwhen the width of the blocking films 58 are greatest at the minimumspacing, for each minimum spacing of blocking films 58.

For example, in the case that the minimum spacing of the blocking films58 is 0.4 μm, the duty ratio is greatest at a point P1 where the widthof the blocking film 58 is 1.6 μm. Also, in the case that the minimumspacing of the blocking films 58 is 0.5 μm, the duty ratio is greatestat a point P2 where the width of the blocking film 58 is 4.6 μm.Similarly, in the case that the minimum spacing of the blocking films 58is 0.8 μm, the duty ratio is greatest at a point P3 where the width ofthe blocking film 58 is 6.0 μm, and in the case that the minimum spacingof the blocking films 58 is 1.5 μm, the duty ratio is greatest at apoint P4 where the width of the blocking film 58 is 10.0 μm.

In the layered-type imaging device 11, the blocking films 58 are formedso that the relationship between the width and minimum spacing of theblocking films 58 has the maximum duty ratio, and FIGS. 41A through 41Dshow a layout of the blocking films 58 formed so as to have the maximumduty ratio.

FIG. 41A shows the blocking films 58 in a layout of the minimum spacingand widths of 0.4 μm and 1.6 μm, respectively, and the duty ratio atthis layout is 64%. FIG. 41B shows the blocking films 58 in a layout ofthe minimum spacing and widths of 0.5 μm and 4.6 μm, respectively, andthe duty ratio at this layout is 81%.

FIG. 41C shows the blocking films 58 in a layout of the minimum spacingand widths of 0.8 μm and 6.0 μm, respectively, and the duty ratio atthis layout is 78%. FIG. 41D shows the blocking films 58 in a layout ofthe minimum spacing and widths of 1.5 μm and 10.0 μm, respectively, andthe duty ratio at this layout is 76%.

FIG. 42 shows the blocking capability of each layout shown in FIGS. 41Athrough 41D. Note that the blocking capability is defined as thetransmittance in the case of 540 nm of light irradiating orthogonally asto the layer of the blocking film 58 when one layer of blocking film 58is disposed. That is to say, we can say that the lower the transmittanceis, the higher the blocking capability is.

As shown in FIG. 42, in the case of a blocking film 58 layout having theminimum spacing and width of 0.5 μm and 4.6 μm, respectively, thehighest blocking capability is the result obtained. For example, asshown in FIGS. 41A through 41D, we can assume that such results would beobtained, from the duty ratio at this layout having been the highest, orthe minimum spacing between the blocking films 58 being similar or lessthan the wavelength of light used in the event of finding thetransmittance.

Also, in the case that the minimum spacing of the blocking films 58 issmallest, i.e. in the case that the minimum spacing of the blockingfilms 58 is 0.4 μm, the blocking capability is lowest, and the result isthat blocking capability is not increased by simply narrowing theminimum spacing of the blocking film 58. That is to say, as shown inFIGS. 41A through 41D, in the case of laying out the blocking films 58with the minimum spacing and widths as 0.4 μm and 1.6 μm, respectively,the duty ratio has the lowest value, whereby we can assume that theblocking capability is low.

Thus, in the layered-type imaging device 11, by employing a layoutwherein the minimum spacing of the blocking films 58 is 0.5 μm which isless than the wavelength of the light to be blocked, and the width is4.6 μm which is the greatest width at the spacing thereof according tothe design rules, the blocking capability can be maximized.

Now, even if the minimum spacing and widths of the blocking films 58 arethe same, when disposing the blocking films 58 on a plane, the blockingfilms 58 can be laid out in multiple patterns. For example, FIGS. 43Aand 43B show an example of blocking film 58 layouts in two patterns.FIG. 43A shows a layout wherein the blocking films 58 are disposed inthe row direction and column direction so as to be in one row. FIG. 43Bshows a layout wherein the blocking films 58 are disposed in one row inthe row direction, and shifted by a half-cycle of a disposing cycle ofthe blocking film 58 for each row in the column direction.

Also, if the blocking capabilities in the two layouts shown in FIGS. 43Aand 43B are similarly found as that described with reference to FIG. 42,the blocking capability in the layout shown in FIG. 43A is 9.0%, and theblocking capability of the layout shown in FIG. 43B is 8.9%. That is tosay, the result is obtained indicating that if the minimum spacing andwidth of the blocking films 58 are the same, even if the layout isdifferent, the blocking capability is approximately the same.

Thus, by forming the blocking films 58 in a rectangular shape, in thewiring layer 51, in a layout according to the design rules shown in FIG.39, the influence from the light emitted by the hot carrier of thetransistors 55 can be reduced to 10% or less.

Next, a configuration example of the blocking films 58 in a two-layerconstruction will be described with reference to FIGS. 44A and 44B. Inthe case of forming the blocking films 58 in a two-layer configuration,blocking capability differs when the amount of shift in the position ofthe blocking film 58-1 in the first layer and the blocking film 58-2 inthe second layer differs.

FIG. 44A shows a two-layer layout wherein the shift between the positionof the blocking film 58-1 in the first layer and the blocking film 58-2in the second layer is half the disposing cycle of the blocking film 58(half-cycle shifting pattern). Also, FIG. 44B shows a two-layer layoutpattern wherein the position of the blocking film 58-1 in the firstlayer and the blocking film 58-2 in the second layer do not shift, i.e.the disposing cycles of the blocking films 58-1 and 58-2 match (samecycle pattern).

With such a two-layer construction layout, when the minimum spacing andthe width of the blocking films 58-1 and 58-2 are set as 0.5 mm and 4.6mm, respectively, the spacing between the blocking film 58-1 and 58-2 isset as 800 nm, and the material and thickness thereof is the same as theblocking film 58 described above, the results thereof are shown in FIG.45.

FIG. 45 shows the results of calculating the blocking capabilities ofwhen the half-cycle shifting pattern is used and when the same cyclepattern is used. As shown in FIG. 45, the results of the blockingcapability when laying out the blocking films 58 in a half-cycleshifting pattern is 0.6%, and the blocking capability when laying outthe blocking films 58 in a same cycle pattern is 3%. That is to say, thehalf-cycle shifting pattern has a result of a higher blocking capabilitythan the same cycle pattern.

Thus, as shown in FIG. 37, in the case of a two-layer construction ofthe blocking films 58-1 and 58-2, not matching the disposing cycle ofthe blocking films 58 in the upper and lower layers is favorable. Notethat the blocking capability is the highest with a layout having a shiftin position between the blocking films 58-1 and 58-2 that is half thedisposing cycle of the blocking film 58, but for example, a layouthaving ⅓ the disposing cycle of the blocking film 58 may be used.

For example, FIG. 46 shows the relation between the shift amount whenthe disposing cycle of the blocking films 58 is shifted in each of theupper and lower layers, and the blocking capability, in the case of atwo-layer construction with the blocking films 58-1 and 58-2.

As shown in FIG. 46, the blocking capability (3%) is the lowest valuewhen the shifting amount is 0°, and the blocking capability (0.6%) isthe highest value when the shifting amount is 180°. With this range, forexample, if the shifting amount is 140°, a certain amount of blockingcapability (e.g. 90% or greater blocking capability when the shiftingamount is) 180° can be obtained. Thus, employing a two-layer layoutpattern so that the shift in position between the blocking film 58-1 inthe first layer and the blocking film 58-2 in the second layer is 140°or greater is favorable. Note that the relation between the shiftingamount and the blocking capability can be set appropriately according tothe spacing between the blocking films 58-1 and 58-2 (wiring spacing inthe vertical direction).

Next, a layout of blocking films 58 employing a line form will bedescribed with reference to FIG. 47. Also, for example, as a blockingfilm 58 form, besides the rectangular shape such as described above, forexample a line shape can be employed. FIG. 47 shows a plan view andcross-sectional view of the blocking films 58 in a line shape layout.

The line shape blocking films 58 are also laid out according to theabove-described design rules. In the example in FIG. 47, a layout isshown of the blocking films 58-1 and 58-2 in a two-layer constructionwith a spacing of 0.8 μm, having the minimum spacing and width of 0.4 μmand 1.6 μm respectively. Also, the shift in position of the blockingfilms 58-1 and 58-2 are half the disposing cycle of the blocking films58. Thus, by employing a line shape blocking film 58, the blocking film58 and wiring 53 can be shared, whereby freedom of design can beimproved.

FIG. 48 shows the result of finding the blocking capability of thelayout in FIG. 47, similar to the description with reference to FIG. 42.As shown in FIG. 48, the blocking capability, in the case of laying outthe blocking films 58-1 and 58-2 in a two-layer construction in a lineshape, is 0.5%. Also, the blocking capability, in the case of laying outthe blocking films 58 in a one-layer construction in a line shape, is14%.

That is to say, when employing the blocking films 58 in a line shape,blocking capability can be greatly improved by using a two-layerconstruction rather than a one-layer configuration. Also, the duty ratiofor the layout shown in FIG. 47 is 80%, and is a smaller value than theduty ratio for the layout shown in FIGS. 44A and 44B, but by forming atwo-layer configuration, greater blocking results can be obtained.

Next, a layout, wherein the blocking films 58-2 in the second layer areonly disposed in the locations where there is a space between theblocking films 58-1 in the first layer, will be described with referenceto FIG. 49. Note that in FIG. 49, the first layer has the blocking films58, but for example, the blocking films 58-2 of the second layer may bedisposed at spaces between the wirings 53 or spaces between the wiring53 and blocking film 58-1 in the first layer.

As shown in FIG. 49, blocking capability can be improved also with alayout wherein blocking films 58-2 of the second layer are disposed atonly the locations that are spaces in the blocking films 58-1 in thefirst layer. Note that with this type of layout, density of the blockingfilms 58-2 of the second layer is lower, and accordingly lower blockingcapability is a concern.

Thus, using the width of overlap when viewing the blocking films 58-1and 58-2 in a plane view as a parameter, the results of find blockingcapabilities are shown in FIG. 50. Note that the blocking capability isthe result of the overlap width being 0 to 1.0 μm and the spacing in thefirst layer and second layer being 0.4 and 0.8 μm. In FIG. 50, thehorizontal axis shows the overlap width, and the vertical axis shows theblocking capability.

As shown in FIG. 46, when the spacing between the first and secondlayers is 0.4 μm, a result is obtained indicating that if the overlapwidth is 0.4 μm or greater, the blocking capability saturates (becomesroughly the same as the blocking capability when the overlap width is 1μm). Also, when the space between the first and second layers is 0.8 μm,a result is obtained indicating that if the overlap width is 0.8 μm orgreater, the blocking capability saturates. That is to say, a result isobtained indicating that, if the overlap width is equal to or greaterthan roughly the same spacing as the first and second layer, even if theoverlap width is further widened, blocking capability does not show agreat change.

Thus, in the layer-type imaging device 11, the overlap width of theblocking films 58-2 is roughly the same as the spacing between the firstand second layers. That is to say, the width of the blocking films 58-2in the second layer is stipulated to be an sum of twice the value of thespacing between the first and second layers plus the spacing between theblocking film 58-1 in the first layer, whereby sufficient blockingcapability can be obtained.

Next, a planar configuration of the wiring layer 51 will be describedwith reference to FIG. 51. In the example in FIG. 51, rectangular shapedblocking films 58 are disposed so as to fill in the spaces that a wiring53 disposed in the wiring layer 51 is not provided, and with the layoutaccording to the design rules, the wiring 53 and blocking films 58coexist. At this time, the width and minimum spacing of the blockingfilms 58 are set between the wirings 53, so as to have the highestblocking capability, according to a pattern in which the wiring 53 isdisposed. Thus, transmitting light that transmits through the wiringlayer 51 can be suppressed to a minimum. Note that line shape blockingfilms 58 may be disposed so as to fill in the spaces where the wirings53 disposed on the wiring layer 51 are not provided.

Also, according to the present technology, for example, light that isnoise, which is other than the light subject to detection, can beapplied to a solid-state imaging device that emits light from apredetermined location, and is not limited to blocking the light emittedfrom the hot carrier as described above, but can be applied to a widerange.

Also, the layer-type imaging device 11 in a configuration such as thatdescribed above can be applied to types of electronic devices such as animaging system such as a digital still camera or digital video camera, acellular phone having an imaging function, or other devices having animaging function.

Also, the layer-type imaging device 11 according to the presenttechnology can be employed, not only in a rear-projection type CMOS typesolid-state imaging device, but also in a front-projection type CMOStype solid state imaging device or CCD type solid-state imaging device.

Example of Electronic Device Using Solid-State Imaging Device

The solid-state imaging device relating to the present technologydescribed above according to the present embodiments can be applied toelectronic devices such as a camera system such as a digital stillcamera or digital video camera, a cellular phone having an imagingfunction, or other devices having an imaging function, for example.

FIG. 52 shows a configuration example of a camera using a solid-stateimaging device as an example of an electronic device relating to thepresent technology. The camera relating to the present embodiment uses avideo camera capable of still images or moving pictures, as an example.A camera 90 has a solid-state imaging device 91, an optical system 93that guides incident light in an light receiving sensor unit of thesolid-state imaging device 91, a shutter device 94, a driving circuit 95that drives the solid-state imaging device 91, and a signal processingcircuit 96 that processes the output signal of the solid-state imagingdevice 91.

The solid-state imaging device 91 applies a solid-state imaging devicein a configuration described according to the embodiments describedabove. The optical system (optical lens) 93 forms image light (incidentlight) form a subject as an image on an imaging face of the solid-stateimaging device 91. Thus, signal load is accumulated in the solid-stateimaging device 91 for a fixed amount of time. This optical system 93 maybe an optical lens system made up of multiple optical lenses. Theshutter device 94 controls the light irradiation periods and lightblocking periods to the solid-state imaging apparatus 91. The drivingcircuit 95 supplies a driving signal to the solid-state imaging device91 and shutter device 94, and with the supplied driving signal (timingsignal), controls the signal output operations of the solid-stateimaging device 91 to the signal processing circuit 95, and controls theshutter operations of the shutter device 94. That is to say, the drivingcircuit 95 performs signal transfer operations from the solid-stateimaging device 91 to the signal processing circuit 96 by supplying adriving signal (timing signal). The signal processing circuit 96performs various types of signal processing as to the signal transferredfrom the solid-state imaging device 91. The picture signal subjected tosignal processing is stored in a storage medium such as memory, or isoutput to a monitor.

According to the electronic device relating to the above-describedpresent embodiments, a solid-state imaging device having favorable lightreceiving properties of one of the above-described first through fifthembodiments is used, whereby high color images and miniaturization ofthe electronic device having an imaging function can be achieved.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. A semiconductor device comprising: a sensorsubstrate including: a first semiconductor substrate; a first wiringlayer formed at a first main surface side of the first semiconductorsubstrate; an insulating material layer formed at a second main surfaceside of the first semiconductor substrate; a conductive layer, wherein aportion of the conductive layer is formed on the insulating materiallayer and has an upper surface side that faces away from the second mainsurface side of the first semiconductor substrate, and wherein the uppersurface side of the portion of the conductive layer includes a concaveportion; a first film formed on the portion of the conductive layer andcovering an inner face of the concave portion; and a second film formedon the first film, wherein at least a portion of the first film and thesecond film are within the concave portion; and a logic substrateincluding: a second semiconductor substrate; and a second wiring layerformed at a first main surface side of the second semiconductorsubstrate, wherein the sensor substrate and the logic substrate arebonded together such that the first wiring layer faces the second wiringlayer, and wherein the conductive layer electrically connects a firstwiring in the first wiring layer and a second wiring in the secondwiring layer.
 2. The semiconductor device according to claim 1, whereinthe first film is a passivation film.
 3. The semiconductor deviceaccording to claim 2, wherein the second film is a passivation film. 4.The semiconductor device according to claim 3, wherein the second filmis an organic film.
 5. The semiconductor device according to claim 3,wherein the second film is an inorganic film.
 6. The semiconductordevice according to claim 1, wherein the second film is a passivationfilm.
 7. The semiconductor device according to claim 1, wherein theconductive layer includes a metallic material embedded in an openingportion of the first semiconductor substrate.
 8. The semiconductordevice according to claim 7, wherein the metallic material is tungsten.9. The semiconductor device of claim 1, wherein the insulating materialextends through the first semiconductor substrate and the first wiringlayer.
 10. The semiconductor device according to claim 1, wherein thefirst wiring layer functions as one or more of a transfer line, anaddress line, a vertical signal line, and a reset line.
 11. Thesemiconductor device according to claim 1, wherein the first filmcontacts both the conductive layer and the insulating material layer.12. The semiconductor device according to claim 1, wherein theconductive layer includes a through-silicon-via that contacts the firstwiring of the first wiring layer.
 13. The semiconductor device accordingto claim 1, wherein the conductive layer includes a first plug, a secondplug, and connective wiring between the first plug and the second plug.14. The semiconductor device according to claim 13, wherein the firstplug extends from the first film to the first wiring in the first wiringlayer.
 15. The semiconductor device according to claim 14, wherein thesecond plug extends from the first film to the second wiring in thesecond wiring layer.
 16. The semiconductor device according to claim 13,wherein a portion of the insulating material layer is located betweenthe first plug and the second plug.
 17. The semiconductor deviceaccording to claim 13, wherein a portion of the insulating materiallayer is located between the connective wiring and the second mainsurface side of the first semiconductor substrate.
 18. The semiconductordevice according to claim 13, wherein the connective wiring is formed soas to be integrated with the first plug and second plug.
 19. Thesemiconductor device according to claim 18, wherein the concave portionis formed in the connective wiring.
 20. The semiconductor deviceaccording to claim 19, wherein the concave portion is formed in theconnective wiring located between the first plug and the second plug.21. The semiconductor device according to claim 13, wherein the secondplug penetrates a first insulating film provided on the first wiringlayer and a second insulating film provided on the second wiring layer.22. The semiconductor device according to claim 13, wherein the firstplug penetrates the first semiconductor substrate.
 23. The semiconductordevice according to claim 13, wherein the first plug, the second plug,and the connective wiring include a metallic material.
 24. Thesemiconductor device according to claim 23, wherein the metallicmaterial is tungsten.
 25. The semiconductor device of claim 13, whereinthe concave portion of the upper surface side of the conductive layer isdisposed above a first semiconductor substrate portion disposed betweenthe first plug and the second plug.
 26. The semiconductor deviceaccording to claim 1, further comprising: a flat film disposed on thesecond film.
 27. The semiconductor device according to claim 26, furthercomprising: a lens material layer disposed on the flat film.
 28. Thesemiconductor device of claim 1, further comprising: at least oneinsulating film between the sensor substrate and the logic substrate,wherein the first film is a first passivation film that includessilicon, and wherein the second film is a second passivation film thatincludes silicon, and wherein the first passivation film covers at leasta portion of the insulating material layer.
 29. The semiconductor deviceaccording to claim 1, wherein the logic substrate includes a logiccircuit configured to process signals output from the sensor substrate.30. An electronic apparatus comprising: a semiconductor deviceincluding: a sensor substrate including: a first semiconductorsubstrate; a first wiring layer formed at a first main surface side ofthe first semiconductor substrate; an insulating material layer formedat a second main surface side of the first semiconductor substrate; aconductive layer, wherein a portion of the conductive layer is formed onthe insulating material layer and has an upper surface side that facesaway from the second main surface side of the first semiconductorsubstrate, and wherein the upper surface side of the portion of theconductive layer includes a concave portion; a first film formed on theportion of the conductive layer and covering an inner face of theconcave portion; and a second film formed on the first film, wherein atleast a portion of the first film and the second film are within theconcave portion; and a logic substrate including: a second semiconductorsubstrate; and a second wiring layer formed at a first main surface sideof the second semiconductor substrate; wherein the sensor substrate andthe logic substrate are bonded together such that the first wiring layerfaces the second wiring layer, and wherein the conductive layerelectrically connects a first wiring in the first wiring layer and asecond wiring in the second wiring layer; and an optical systemconfigured to guide incident light to the semiconductor device.